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Zatko, F. J., P. Martin et R. C. Bahler. « Time course of systolic loading is an important determinant of ventricular relaxation ». American Journal of Physiology-Heart and Circulatory Physiology 252, no 3 (1 mars 1987) : H461—H466. http://dx.doi.org/10.1152/ajpheart.1987.252.3.h461.
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We studied the dependency of left ventricular relaxation on the timing of an abrupt increase in systolic load. In 10 canine isolated heart-lung preparations, a load step of 15 mmHg was imposed at specific intervals throughout systole, and the time of loading was defined as the interval from the R wave to the completion of the load step (R-load interval). Preload was held constant. The right atrium was paced at a cycle length of 450 ms. The decay of left ventricular pressure during isovolumic relaxation was described by a single exponential time constant (Texp). Load effects on isovolumic relaxation were expressed as a percent change in Texp as compared with Texp of the beat preceding the load intervention. Loads imposed early in systole consistently prolonged Texp [mean delta Texp = +17.01 +/- 1.64% (SE) for R-load intervals less than or equal to 120 ms]. Load changes late in systole consistently abbreviated Texp [mean delta Texp = -9.49 +/- 0.86% (SE) for R-load intervals greater than or equal to 130 ms]. The transition from augmentation to diminution of Texp always occurred when the R-load interval was 120-130 ms. The mean time interval of electromechanical systole for the test beats was not significantly different (P greater than or equal to 0.05) from that of the control beats [R-load intervals less than or equal to 120: test = 247.0 +/- 27.8 (SD) ms; control = 246.6 +/- 26.8 (SD) ms] [R-load intervals greater than or equal to 130: test = 243.3 +/- 29.1 (SD) ms; control = 243.8 +/- 28.4 (SD) ms].(ABSTRACT TRUNCATED AT 250 WORDS)
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Her, Charles, et Elizabeth A. M. Frost. « Assessment of right ventricular function by right ventricular systolic time intervals in acute respiratory failure ». Critical Care Medicine 27, no 12 (décembre 1999) : 2703–6. http://dx.doi.org/10.1097/00003246-199912000-00017.
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Bodh, Deepti, Mozammel Hoque et Abhishek Chandra Saxena. « Echocardiographic study of healthy Indian Spitz dogs with normal reference ranges for the breed ». Veterinary World 12, no 6 (juin 2019) : 740–47. http://dx.doi.org/10.14202/vetworld.2019.740-747.
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Aim: The present study was aimed to determine the normal reference values of M-mode echocardiographic measurements in healthy Indian Spitz dogs and evaluate the influence of gender and body weight on these measurements. Materials and Methods: M-mode echocardiography was performed in twenty-four clinically healthy conscious Indian Spitz dogs, aged 3-5 years and weighing 7-18 kg. Measurements were made from the right parasternal long axis left ventricular outflow tract view of the heart. The parameters recorded were: Left ventricular internal dimension, interventricular septal thickness and left ventricular posterior wall thickness during diastole and systole, left atrial diameter, aortic root diameter, left ventricular systolic functional parameters, and indices and mitral valve parameters. Results: M-mode echocardiographic measurements in healthy Indian Spitz dogs were standardized. Gender had no influence on echocardiographic measurements except mitral valve excursion amplitude and time interval between onset and end of mitral valve closure, which were significantly (p<0.05) higher in females than males. Left ventricular internal dimension at end-diastole, left ventricular internal dimension at end-systole, left ventricular posterior wall dimension at end-systole, end-diastolic volume, end-systolic volume, stroke volume, cardiac output, left ventricular ejection time, and mitral valve excursion amplitude correlated significantly (p<0.05) with body weight in Indian Spitz dogs. Conclusion: Data obtained in the present study can be used as breed-specific reference values for cardiac disease diagnosis as well as for future studies in Indian Spitz dogs.
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Lee, Simon, Irene D. Lytrivi, Zhanna Roytman, Hyun-Sook Helen Ko, Cheryl Vinograd et Shubhika Srivastava. « Cardiomyopathy in children : Can we rely on echocardiographic tricuspid regurgitation gradient estimates of right ventricular and pulmonary arterial pressure ? » Cardiology in the Young 26, no 7 (4 mars 2016) : 1406–13. http://dx.doi.org/10.1017/s1047951116000020.
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AbstractIntroductionAgreement between echocardiography and right heart catheterisation-derived right ventricular systolic pressure is modest in the adult heart failure population, but is unknown in the paediatric cardiomyopathy population.MethodsAll patients at a single centre from 2001 to 2012 with a diagnosis of cardiomyopathy who underwent echocardiography and catheterisation within 30 days were included in this study. The correlation between tricuspid regurgitation gradient and catheterisation-derived right ventricular systolic pressure and mean pulmonary artery pressure was determined. Agreement between echocardiography and catheterisation-derived right ventricular systolic pressure was assessed using Bland–Altman plots. Analysis was repeated for patients who underwent both procedures within 7 days. Haemodynamic data from those with poor agreement and good agreement between echocardiography and catheterisation were compared.ResultsA total of 37 patients who underwent 48 catheterisation procedures were included in our study. The median age was 11.8 (0.1–20.6 years) with 22 males (58% total). There was a modest correlation (r=0.65) between echocardiography and catheterisation-derived right ventricular systolic pressure, but agreement was poor. Agreement between tricuspid regurgitation gradient and right ventricular systolic pressure showed wide 95% limits of agreement. There was a modest correlation between the tricuspid regurgitation gradient and mean pulmonary artery pressure (r=0.6). Shorter time interval between the two studies did not improve agreement. Those with poor agreement between echocardiography and catheterisation had higher right heart pressures, but this difference became insignificant after accounting for right atrial pressure.ConclusionTransthoracic echocardiography estimation of right ventricular systolic pressure shows modest correlation with right heart pressures, but has limited agreement and may underestimate the degree of pulmonary hypertension in paediatric cardiomyopathy patients.
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Hsieh, Kai S., Stephen P. Sanders, Steven D. Colan, Debbie MacPherson et Cynthia Holland. « Right ventricular systolic time intervals : Comparison of echocardiographic and Doppler-derived values ». American Heart Journal 112, no 1 (juillet 1986) : 103–7. http://dx.doi.org/10.1016/0002-8703(86)90686-1.
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Shaffer, Elizabeth M., A. Rebecca Snider, Gerald A. Serwer, Jane Peters et Patricia A. Reynolds. « Effect of sampling site on Doppler-derived right ventricular systolic time intervals ». American Journal of Cardiology 65, no 13 (avril 1990) : 950–52. http://dx.doi.org/10.1016/0002-9149(90)91452-c.
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Her, Charles, Hideo Koike et James O'Connell. « ESTIMATED RIGHT VENTRICULAR SYSTOLIC TIME INTERVALS FOR THE ASSESSMENT OF RIGHT VENTRICULAR FUNCTION IN ACUTE RESPIRATORY DISTRESS SYNDROME ». Shock 31, no 5 (mai 2009) : 460–65. http://dx.doi.org/10.1097/shk.0b013e31818ba1f4.
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Nguyen Quoc, Thai, et Vu Nguyen Anh. « STUDY OF RIGHT VENTRICULAR DP/DT INDEX IN PATIENT WITH MITRAL STENOSIS BY DOPPLER ECHOCARDIOGRAPHY ». Volume 8 Issue 3 8, no 3 (juin 2018) : 19–30. http://dx.doi.org/10.34071/jmp.2018.3.3.
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Objectives: To use echocardiographic dP/dt to assess the right ventricular function in patients with mitral stenosis. Subjects and methods: 48 patients with pulmonary hypertension due to mitral stenosis with everage age of 52.75 ± 13.09 years, were hospitalized in Department of Internal Cardiology and Cardiothoracic Department of Hue Central Hospital about time 3/2015 to 7/2017. All of patients had been measured right ventricular dP/dt index by Doppler echocardiograph. The method of research is a cross sectional study. Result: DP/dt should be reduced to the severity of pulmonary hypertension in patients with mitral stenosis. There was a statistically significant difference between right ventricular dP/dt of patients with mild to moderate systolic pulmonary hypertension with severe systolic pulmonary hypertension patients. There was a very negative correlation between right ventricular dP/dt rate and NYHA heart failure classification (r = -0.524 and p<0.0001), the negative correlation between right ventricular dP/dt and systolic pulmonary artery pressure (r = - 0.599 and p<0.0001). Positive correlation between right ventricular dP/dt and mitral valve area (r = 0.341 and p<0.05) and positive correlation between right ventricular dP/dt and TAPSE (r = 0.538 and p <0.001). Conclusion: dP/dt may be used to evaluate right ventricular function in patients with pulmonary hypertension due to mitral stenosis. Key words: Tricuspid Annular Plane Systolic Excursion (TAPSE), right ventrical dP/dt
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Huez, Sandrine, Kathleen Retailleau, Philippe Unger, Adriana Pavelescu, Jean-Luc Vachiéry, Geneviève Derumeaux et Robert Naeije. « Right and left ventricular adaptation to hypoxia : a tissue Doppler imaging study ». American Journal of Physiology-Heart and Circulatory Physiology 289, no 4 (octobre 2005) : H1391—H1398. http://dx.doi.org/10.1152/ajpheart.00332.2005.
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Hypoxia has been reported to alter left ventricular (LV) diastolic function, but associated changes in right ventricular (RV) systolic and diastolic function remain incompletely documented. We used echocardiography and tissue Doppler imaging to investigate the effects on RV and LV function of 90 min of hypoxic breathing (fraction of inspired O2 of 0.12) compared with those of dobutamine to reproduce the same heart rate effects without change in pulmonary vascular tone in 25 healthy volunteers. Hypoxia and dobutamine increased cardiac output and tricuspid regurgitation velocity. Hypoxia and dobutamine increased LV ejection fraction, isovolumic contraction wave velocity (ICV), acceleration (ICA), and systolic ejection wave velocity (S) at the mitral annulus, indicating increased LV systolic function. Dobutamine had similar effects on RV indexes of systolic function. Hypoxia did not change RV area shortening fraction, tricuspid annular plane systolic excursion, ICV, ICA, and S at the tricuspid annulus. Regional longitudinal wall motion analysis revealed that S, systolic strain, and strain rate were not affected by hypoxia and increased by dobutamine on the RV free wall and interventricular septum but increased by both dobutamine and hypoxia on the LV lateral wall. Hypoxia increased the isovolumic relaxation time related to RR interval (IRT/RR) at both annuli, delayed the onset of the E wave at the tricuspid annulus, and decreased the mitral and tricuspid inflow and annuli E/A ratio. We conclude that hypoxia in normal subjects is associated with altered diastolic function of both ventricles, improved LV systolic function, and preserved RV systolic function.
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Xu, Hongyuan, Jinyi Li, Guoqiang Zhong, Lin Li, Chuang Huang, Peng Guo, Yizhao Chen et Tao He. « Characteristics of the Dynamic Electrocardiogram in the Elderly with Nonvalvular Atrial Fibrillation Combined with Long R-R Intervals ». Evidence-Based Complementary and Alternative Medicine 2021 (10 novembre 2021) : 1–7. http://dx.doi.org/10.1155/2021/4485618.
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Objective. To investigate the characteristics of dynamic electrocardiogram and their clinical implications in elderly patients with nonvalvular atrial fibrillation combined with long R-R intervals. Methods. Elderly patients diagnosed with nonvalvular atrial fibrillation who were admitted as an inpatient or attended the outpatient department from January 2015 to January 2020 were selected. Patients were divided into two groups based on the presence of a long R-R interval. The characteristics and therapeutic significance of dynamic electrocardiogram between the two groups were compared. Results. A total of 532 patients were included in our analyses. Of these, 399 patients were in the long R-R interval group and 133 in the nonlong R-R interval group. In 399 patients, there were 48,840 long R-R intervals manifested within 24 hours. The average, slowest, and fastest ventricular rates during sleep time were higher than those in nonsleep time, while the number of long R-R intervals in sleep time was significantly smaller than that in nonsleep time ( P < 0.05 ). Clinical parameters including dizziness/syncope, cerebral infarction, ST-segment changes, platelet count, average hematocrit, prothrombin time (PT), left ventricular systolic function, end-diastolic diameter, pulmonary artery pressure, and left ventricular ejection fraction were comparable between the groups ( P > 0.05 ). When compared with the nonlong R-R interval group, the level of C-reactive protein was slightly lower in the long R-R interval group ( P < 0.05 ). In addition, the long R-R interval group had a higher incidence of atrial premature beats but a lower incidence of ventricular premature beats. Furthermore, the probability of long R-R interval combined with paroxysmal atrial tachycardia, transient ventricular arrest, second-degree atrioventricular block, and complete or incomplete right bundle branch block was higher than that of nonlong R-R interval ( P < 0.05 ). In patients with long R-R interval >3 s, the risk of having second-degree atrioventricular block and complete or incomplete right bundle branch block was significantly lower, while the risk of having transient ventricular arrest was higher when compared to patients with long R-R intervals of 2-3 s ( P < 0.05 P). Conclusions. Long R-R interval is a common electrocardiographic phenomenon among the elderly with nonvalvular atrial fibrillation. The long R-R interval mostly occurs in nonsleeping time. The average ventricular rate, slowest ventricular rate, and fastest ventricular rate of sleep time are higher than nonsleeping time. Analysis of the characteristics of the dynamic electrocardiogram of these patients may shed light on the mechanisms for long R-R intervals, including the likelihood of concealed conduction and physiological interference in the atrioventricular node, overspeed inhibition, increased vagus nerve tension, or pathological atrioventricular block.
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Chirife, Raul, et G. Aurora Ruiz. « 216-68 : Cardiac Malfunction Detected by Systolic Time Intervals During Right Ventricular Pacing ». EP Europace 18, suppl_1 (juin 2016) : i158. http://dx.doi.org/10.1093/europace/18.suppl_1.i158c.
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GUERRERO, JOSE E., JAVIER MUÑOZ, BRAULIO DE LA CALLE, RICARDO VALERO et MARIA T. ALBERCA. « Right ventricular systolic time intervals determined by means of a pulmonary artery catheter ». Critical Care Medicine 20, no 11 (novembre 1992) : 1529–37. http://dx.doi.org/10.1097/00003246-199211000-00009.
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Silberbach, G. Michael, Randall L. Imus, Robert W. McDonald, Kerri Andrilenas, Mary J. Rice et Mark D. Reller. « Effect of patent ductus arteriosus on doppler-derived right ventricular systolic time intervals ». Pediatric Cardiology 14, no 3 (juillet 1993) : 155–58. http://dx.doi.org/10.1007/bf00795644.
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Tabata, Tomotsugu, Richard A. Grimm, Junko Asada, Zoran B. Popović, Hirotsugu Yamada, Neil L. Greenberg, Don W. Wallick et al. « Determinants of LV diastolic function during atrial fibrillation : beat-to-beat analysis in acute dog experiments ». American Journal of Physiology-Heart and Circulatory Physiology 286, no 1 (janvier 2004) : H145—H152. http://dx.doi.org/10.1152/ajpheart.00588.2003.
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Left ventricular (LV) diastolic function during atrial fibrillation (AF) remains poorly understood due to the complex interaction of factors and beat-to-beat variability. The purpose of the present study was to elucidate the physiological determinants of beat-to-beat changes in LV diastolic function during AF. The RR intervals preceding a given cardiac beat were measured from the right ventricular electrogram in 12 healthy open-chest mongrel dogs during AF. Doppler echocardiography and LV pressure and volume beat-to-beat analyses were performed. The LV filling time (FT) and early diastolic mitral inflow velocity-time integral ( Evti) were measured using the pulsed Doppler method. The LV end-diastolic volume (EDV), peak systolic LV pressure (LVP), minimum value of the first derivative of LV pressure curve (dP/d tmin), and the time constant of LV pressure decay (τ) were evaluated with the use of a conductance catheter for 100 consecutive cardiac cycles. Beat-to-beat analysis revealed a cascade of important causal relations. LV-FT showed a significant positive linear relationship with Evti ( r = 0.87). Importantly, there was a significant positive linear relationship between the RR interval and LV-EDV in the same cardiac beat ( r = 0.53). Consequently, there was a positive linear relationship between LV-EDV and subsequent peak systolic LVP ( r = 0.82). Furthermore, there were significant positive linear and negative curvilinear relationships between peak systolic LVP and dP/d tmin ( r = 0.95) and τ ( r = –0.85), respectively, in the same cardiac beat. In addition, there was a significant negative curvilinear relationship between dP/d tmin and τ ( r = –0.86). We have concluded that the determinants of LV diastolic function in individual beats during AF depend strongly on the peak systolic LVP. This suggests that the major benefit of slower ventricular rate appears related to lengthening of LV filling interval, promoting subsequent higher peak systolic LVP and greater LV relaxation.
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Pahl, Elfriede, et Samuel S. Gidding. « Echocardiographic Assessment of Cardiac Function During Respiratory Syncytial Virus Infection ». Pediatrics 81, no 6 (1 juin 1988) : 830–34. http://dx.doi.org/10.1542/peds.81.6.830.
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Respiratory syncytial virus infection has been associated with increased morbidity and mortality in infants with underlying cardiac and pulmonary disease. To understand better the cardiopulmonary interaction in patients with acute respiratory syncytial virus bronchiolitis, we performed M-mode echocardiograms and pulsed Doppler assessment of pulmonary arterial flow in 19 patients with structurally normal hearts during acute illness. Studies were repeated in 11 of these patients following complete recovery. Based on severity of respiratory compromise, patients were grouped into those with severe illness (ten patients) or mild illness (nine patients). Left ventricular dimensions and shortening fraction were used to assess left ventricular function. Right ventricular systolic time intervals and specific Doppler flow velocity measurements were used to assess right ventricular function and elevation of pulmonary artery pressure. Comparisons were made between patients with severe and mild illness and between acute and follow-up studies. No statistically significant differences in left ventricular function, right ventricular systolic time intervals, or Doppler flow measurements were observed. We conclude that in patients with structurally normal hearts, respiratory syncytial virus bronchiolitis is not associated with significant depression of cardiac performance or elevation in pulmonary resistance.
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Lubocka, Paulina, et Robert Sabiniewicz. « What Is the Importance of Electrocardiography in the Routine Screening of Patients with Repaired Tetralogy of Fallot ? » Journal of Clinical Medicine 10, no 19 (22 septembre 2021) : 4298. http://dx.doi.org/10.3390/jcm10194298.
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Background: In patients following complete repair of the tetralogy of Fallot, the duration of the QRS complex is associated with the size and mechanical function of the right ventricle, which are contemporarily assessed by cardiac magnetic resonance (CMR). Methods: 38 patients aged 18.0–54.9 years (median age 24.9 years) who had undergone complete repair of the tetralogy of Fallot were examined using CMR and concomitant 24 h ambulatory electrocardiography monitoring. We used statistical analysis to investigate the correlations between electrocardiographic parameters (heart rate, HR; PQ interval, PQ; QRS duration, QRS; and corrected QT interval, QTc) and CMR results (right ventricular ejection fraction, RVEF; right ventricular end-diastolic volume index, RVEDVI; and right ventricular end-systolic volume index, RVESVI) for patients after early and late repair. Results: The ECG-based parameters were not correlated with time since repair. There were significant correlations between QRS duration and RVEF (r = −0.61), RVEDVI (r = 0.56), and RVESVI (r = 0.54) for early operated patients but not for late-operated patients. No other substantial correlations were reported. Conclusion: Despite its role in screening for arrhythmias, electrocardiography has a limited role as a predictor of morphology and function of the right ventricle in patients after repair of the tetralogy of Fallot.
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Brailovsky, Yevgeniy, Vladimir Lakhter, Ido Weinberg, Katerina Porcaro, Jeremiah Haines, Stephen Morris, Dalila Masic et al. « Right Ventricular Outflow Doppler Predicts Low Cardiac Index in Intermediate Risk Pulmonary Embolism ». Clinical and Applied Thrombosis/Hemostasis 25 (1 janvier 2019) : 107602961988606. http://dx.doi.org/10.1177/1076029619886062.
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Intermediate-risk pulmonary embolism (PE) has variable outcomes. Current risk stratification models lack the positive predictive value to identify patients at highest risk of PE-related mortality. We identified intermediate-risk PE patients who underwent catheter-based interventions and right heart catheterization (RHC) and identified those with low cardiac index (CI < 2.2 L/min/m2). We utilized regression models to identify echocardiographic predictors of low CI and Kaplan Meier curve to evaluate PE-related mortality when stratified by the echocardiographic predictor. Of 174 intermediate-risk PE patients, 41 underwent RHC. Within this cohort, 46.3% had low CI. Univariable linear regression identified right ventricular outflow tract velocity time integral (RVOT VTI), right/left ventricular ratio, S prime, inferior vena cava diameter, and pulmonary artery systolic pressure as potential predictors of low CI. Multivariable linear regression identified RVOT VTI as significant predictor of low CI (β coefficient 0.124, 95% confidence interval [CI]: 0.01-0.24, P = .034). Right ventricular outflow tract velocity time integral <9.5 cm was associated with increased PE-related mortality, P = .002. A substantial proportion of intermediate-risk PE patients referred for catheter-based interventions had low CI despite normotension. Right ventricular outflow tract velocity time integral was a significant predictor of low CI. Low RVOT VTI was associated with increased PE-related mortality.
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Wieshammer, Siegfried, Fritz S. Keck, Josef Waitzinger, Eberhard Henze, Ulrich Loos, Vinzenz Hombach et Ernst F. Pfeiffer. « Acute hypothyroidism slows the rate of left ventricular diastolic relaxation ». Canadian Journal of Physiology and Pharmacology 67, no 9 (1 septembre 1989) : 1007–10. http://dx.doi.org/10.1139/y89-158.
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The effect of acute thyroid hormone deficiency on left ventricular diastolic filling was studied by radionuclide ventriculography with simultaneous right heart catheterization in nine athyreotic patients without cardiovascular disease. The patients were studied when they were hypothyroid and when they were euthyroid on replacement therapy. Peak filling rate and the time to peak filling were used to characterize diastolic function. The time to peak filling was defined as the interval from end-systole on the radionuclide time–volume curve to the time of occurrence of peak filling. The peak filling rate was determined in absolute terms from the normalized radionuclide peak filling rate and from the end-diastolic volume, which was derived from the radionuclide ejection fraction and from the thermodilution stroke volume. In all patients, the values for peak filling rate were lower in the hypothyroid than in the euthyroid state (287 ± 91 mL/s vs. 400 ± 118 mL/s, Δ = 41 ± 13%, p < 0.01). Peak filling always occurred during the first half of the diastolic interval. The time to peak filling was not significantly affected by the thyroid state (170 ± 10 ms vs. 159 ± 21 ms, Δ = 7 ± 10%). Left ventricular filling pressure as reflected by the pulmonary capillary wedge pressure and end-systolic volume were similar in both thyroid states (6 ± 2 mmHg vs. 8 ± 2 mmHg (1 mmHg = 133.32 Pa) and 32 ± 11 mL vs. 32 ± 7 mL, respectively). The data suggest that the rate of active diastolic relaxation is decreased in short-duration hypothyroidism. This may be due to a depressed activity of the sarcoplasmic reticular calcium pump which is under thyroid control.Key words: hypothyroidism, left ventricular diastolic function, radionuclide ventriculography.
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Wang, Yi-Chih, Chih-Chieh Yu, Fu-Chun Chiu, Vincent Splett, Ruth Klepfer, Kathryn Hilpisch, Chia-Ti Tsai, Ling-Ping Lai, Juey-Jen Hwang et Jiunn-Lee Lin. « Acute Effects of Biventricular Pacing in Heart Failure Patients with a Normal Ejection Fraction and Mechanical Dyssynchrony ». Cardiology 130, no 2 (2015) : 112–19. http://dx.doi.org/10.1159/000368795.
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Objectives: We tested the acute effects of resynchronization in heart failure patients with a normal (>50%) left ventricular (LV) ejection fraction (HFNEF) and mechanical dyssynchrony. Methods: Twenty-four HFNEF patients (72 ± 6 years, 5 male) with mechanical dyssynchrony (standard deviation of electromechanical time delay among 12 LV segments >35 ms) were studied with temporary pacing catheters in the right atrium, LV, and right ventricle (RV), and high-fidelity catheters for pressure recording. Using selected atrioventricular (AV) intervals of 60, 90, 120, 150, and 180 ms to optimize transmitral flow during simultaneous biventricular pacing, the RV-LV (VV) interval was then evaluated at RV30, RV15, 0, LV15, LV30, and LV45 (RV or LV indicates which ventricle was paced first, the number indicates by how many ms). Results: During simultaneous pacing, longer AV intervals were associated with improved LV pressure-derivative minimums and increased aortic pressures (p < 0.05 vs. normal sinus rhythm). In the VV interval from RV30 to LV45, there was a graded increase in the aortic velocity time integral and a decrease in dyssynchrony during simultaneous or LV-first pacing (p < 0.05 vs. normal sinus rhythm). Conclusions: For HFNEF patients with mechanical dyssynchrony, acute simultaneous biventricular or LV-first pacing with longer AV intervals reduced mechanical dyssynchrony and improved diastolic and systolic hemodynamics.
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Nelle, M., C. Hoecker et O. Linderkamp. « Effects of red cell transfusion on pulmonary blood flow and right ventricular systolic time intervals in neonates ». European Journal of Pediatrics 156, no 7 (26 juin 1997) : 553–56. http://dx.doi.org/10.1007/s004310050661.
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Ran, Liyu, Wuwan Wang, Francesco Secchi, Yajie Xiang, Wenhai Shi et Wei Huang. « Percutaneous pulmonary valve implantation in patients with right ventricular outflow tract dysfunction : a systematic review and meta-analysis ». Therapeutic Advances in Chronic Disease 10 (janvier 2019) : 204062231985763. http://dx.doi.org/10.1177/2040622319857635.
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Background: Pulmonary valve replacement is required for patients with right ventricular outflow tract (RVOT) dysfunction. Surgical and percutaneous pulmonary valve replacement are the treatment options. Percutaneous pulmonary valve implantation (PPVI) provides a less-invasive therapy for patients. The aim of this study was to evaluate the effectiveness and safety of PPVI and the optimal time for implantation. Methods: We searched PubMed, EMBASE, Clinical Trial, and Google Scholar databases covering the period until May 2018. The primary effectiveness endpoint was the mean RVOT gradient; the secondary endpoints were the pulmonary regurgitation fraction, left and right ventricular end-diastolic and systolic volume indexes, and left ventricular ejection fraction. The safety endpoints were the complication rates. Results: A total of 20 studies with 1246 participants enrolled were conducted. The RVOT gradient decreased significantly [weighted mean difference (WMD) = −19.63 mmHg; 95% confidence interval (CI): −21.15, −18.11; p < 0.001]. The right ventricular end-diastolic volume index (RVEDVi) was improved (WMD = −17.59 ml/m²; 95% CI: −20.93, −14.24; p < 0.001), but patients with a preoperative RVEDVi >140 ml/m² did not reach the normal size. Pulmonary regurgitation fraction (PRF) was notably decreased (WMD = −26.27%, 95% CI: −34.29, −18.25; p < 0.001). The procedure success rate was 99% (95% CI: 98–99), with a stent fracture rate of 5% (95% CI: 4–6), the pooled infective endocarditis rate was 2% (95% CI: 1–4), and the incidence of reintervention was 5% (95% CI: 4–6). Conclusions: In patients with RVOT dysfunction, PPVI can relieve right ventricular remodeling, improving hemodynamic and clinical outcomes.
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Botto, Giovanni Luca, Assunta Iuliano, Eraldo Occhetta, Giuseppina Belotti, Giovanni Russo, Monica Campari, Sergio Valsecchi et Giuseppe Stabile. « A randomized controlled trial of cardiac resynchronization therapy in patients with prolonged atrioventricular interval : the REAL-CRT pilot study ». EP Europace 22, no 2 (13 novembre 2019) : 299–305. http://dx.doi.org/10.1093/europace/euz321.
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Abstract Aims A prolonged PR interval is known to be associated with increased mortality and a higher risk of developing atrial fibrillation (AF). We tested the hypothesis that cardiac resynchronization therapy (CRT) is superior to conventional dual-chamber pacing with algorithms for right ventricular pacing avoidance (DDD-VPA) in preserving systolic and diastolic function and in preventing new-onset AF in patients with normal systolic function, indication for pacing and prolonged atrioventricular conduction (PR interval ≥220 ms). Methods and results We randomly assigned 82 patients with ejection fraction >35%, indication for pacing and PR interval ≥220 ms to CRT or to DDD-VPA. On 12-month follow-up examination, the study and control arms did not differ in terms of left ventricular end-systolic volume (44 ± 17 mL vs. 47 ± 16 mL, P = 0.511) or ejection fraction (55 ± 6% vs. 57 ± 8%, P = 0.291). The E to A mitral wave amplitude ratio was higher in the CRT arm (1.3 ± 1.3 vs. 0.8 ± 0.4, P = 0.046) and the E wave deceleration time was longer (262 ± 83 ms vs. 205 ± 51 ms, P = 0.027). Left atrial volume was smaller in the CRT arm (64 ± 17 mL vs. 84 ± 25 mL, P = 0.035). Moreover, the functional class was lower in CRT patients (1.4 ± 0.6 vs. 1.8 ± 0.5, P = 0.010). During follow-up, CRT was associated with a lower risk of new-onset AF [hazard ratio = 0.37 (0.13–0.98), P = 0.046]. Conclusion Cardiac resynchronization therapy proved superior to DDD-VPA in terms of better diastolic function, less left atrial enlargement and lower risk of new-onset AF, at 12 months. These data need to be confirmed in a larger trial with longer follow-up. Clinical trial registration URL: http://clinicaltrials.gov/ Identifier: NCT02150538
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Johard, Einar, Anna Tidholm, Ingrid Ljungvall, Jens Häggström et Katja Höglund. « Effects of sedation with dexmedetomidine and buprenorphine on echocardiographic variables, blood pressure and heart rate in healthy cats ». Journal of Feline Medicine and Surgery 20, no 6 (18 juillet 2017) : 554–62. http://dx.doi.org/10.1177/1098612x17720327.
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Objectives Sedative agents are occasionally used to enable echocardiographic examination when screening cats for heart disease, such as hypertrophic cardiomyopathy (HCM). Owing to their haemodynamic effects, sedative agents may alter echocardiographic measurements. The aim of the study was to evaluate the effects of the sedative combination dexmedetomidine and buprenorphine on echocardiographic variables, blood pressure (BP) and heart rate (HR) in healthy cats. Methods Fifty healthy, client-owned cats were prospectively recruited and included after physical examination. Cats were sedated intramuscularly with dexmedetomidine and buprenorphine, according to body weight. Blood pressure and HR measurements, echocardiographic and Doppler examinations were performed prior to sedation and repeated once cats had achieved acceptable sedation. Results Left ventricular internal diameter at end-diastole and systole, right ventricular internal diameter at end-diastole, left atrium (LA), pulmonary artery (PA) deceleration time, and systolic, diastolic and mean arterial blood pressure increased after sedation ( P ⩽0.022). Aortic and PA maximum velocity, fractional shortening, PA acceleration/deceleration time and HR decreased after sedation ( P <0.0001). Interventricular septum at end-diastole and systole, left ventricular posterior wall at end-diastole and systole, aortic diameter (Ao), left atrial/aortic diameter (LA/Ao) and pulmonic acceleration time did not change. Conclusions and relevance Blood pressure increased and HR decreased post-sedation. While wall thickness and LA/Ao were not affected by sedation, indices of LA and left ventricular size increased. Further studies are needed using cats with HCM to assess the effect of this sedative combination on HCM screening results.
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Karasu, Betül Banu, et Hüseyin Ayhan. « Early Impairment of Right Ventricular Functions in Patients with Moderate Asthma and the Role of Isovolumic Acceleration ». Koşuyolu Heart Journal 25, no 2 (1 août 2022) : 157–64. http://dx.doi.org/10.51645/khj.2022.m207.
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Introduction: Asthma is a common chronic lung disease that affects people all over the world. Pulmonary hypertension and right ventricular (RV) dysfunction are possible complications that may develop in the advanced stages of asthma. However, the number of studies investigating asthma and its implications on new RV parameters are very rare. This study aims to evaluate the RV functions in patients with moderate asthma before the development of pulmonary hypertension. Patients and Methods: Forty-one patients with moderate asthma and 40 healthy individuals were enrolled in this case-control study. All participants underwent a detailed two-dimensional echocardiographic examination. RV functions were measured through RV isovolumic acceleration (IVA) index in addition to conventional parameters. RV IVA, a tissue doppler derived parameter, was calculated as the ratio between maximum isovolumic myocardial velocity during isovolumic contraction and the time interval from the onset of this wave to the time at its maximum velocity. Results: There were no significant differences between the two groups in terms of baseline clinical characteristics, laboratory findings and echocardiographic parameters measuring left ventricular functions (p> 0.05). In asthmatic patients, RV isovolumic relaxation time and RV myocardial performance index were higher (p= 0.027 and p<0.001 respectively), while RV fractional area change, tricuspid annular plane systolic excursion (TAPSE) and RV IVA values were all lower (p<0.001). RV IVA was found to be inversely proportional to asthma duration. TAPSE [β= 0.632, 95% CI= (0.121) - (0.225), p<0.001] and pulmonary artery systolic pressure [β= -0.188, 95% CI= (-0.057) - (-0.003), p= 0.032] were shown as independent predictors of RV IVA. Conclusion: Asthma is an important disease that may result in subclinical RV dysfunction even before the development of pulmonary hypertension. RV IVA, an easily obtained and load-independent parameter, may be a useful and reliable index that sensitively analyzes subtle deteriorations in the contractile function of RV in asthmatic patients. RV IVA may also correlate with asthma duration.
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Ayabakan, Canan, et Süheyla Özkutlu. « Normal patterns of flow in the superior caval, hepatic and pulmonary veins as measured using Doppler echocardiography during childhood ». Cardiology in the Young 13, no 2 (avril 2003) : 143–51. http://dx.doi.org/10.1017/s1047951103000283.
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To date, no reference values have been provided for right and left atrial filling in normal children. The aim of our study, therefore, was to characterize measurements of superior caval, hepatic, and pulmonary venous flow using Doppler echocardiography in a large group of normal children to reflect the effects of age, body mass index, sex, heart rate and respiration.Doppler echocardiographic examinations of the superior caval, hepatic and pulmonary veins were performed during inspiration and expiration in 72 healthy children with a mean age of 6.73 ± 5.10 years. The subjects were segregated into four age groups, namely infants <2 years, preschool children between the ages of 2 and 7 years, children of school age between 7 and 11 years, and adolescents older than 11 years.Age has significant effect on the systolic and reverse atrial flows within the superior caval vein (p < 0.05). No change in the Doppler velocities was observed related to body mass index or sex. All peak systolic velocities decreased significantly during expiration (p < 0.05). This decrease was most prominent in the hepatic vein (26%), but less remarkable in the superior caval vein (5.7%) and the pulmonary veins (3.9%). During expiration, the peak diastolic flow in the superior caval and the hepatic veins decreased, while the reverse atrial flow in the hepatic vein increased (p < 0.05). Pulmonary venous velocities were similar in all age groups (p > 0.05). Except for the systolic pulmonary venous velocities, these parameters were not influenced by respiration (p > 0.05). The diastolic time, the interval between reverse atrial flow and ventricular systole reflected by the R wave on the electrocardiogram, and the interval between ventricular systole and diastolic flow, were negatively correlated with heart rate (p < 0.05; r = −0.35, −0.85, and −0.8 respectively), and positively correlated with age (p < 0.05; r = 0.3, 0.8, and 0.7 respectively). They were not influenced by respiration.Our study provides data of the patterns and the normal ranges of velocities of superior caval, hepatic, and pulmonary venous flow in a series of normal children. The results can now be used for comparison with the patterns found in the setting of disease.
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Cantinotti, Massimiliano, Pietro Marchese, Marco Scalese, Eliana Franchi, Nadia Assanta, Martin Koestenberger, Alessandra Pizzuto et al. « Atrial Function Impairments after Pediatric Cardiac Surgery Evaluated by STE Analysis ». Journal of Clinical Medicine 11, no 9 (29 avril 2022) : 2497. http://dx.doi.org/10.3390/jcm11092497.
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Background: Applications of atrial speckle tracking echocardiography (STE) strain (ε) analysis in pediatric cardiac surgery have been limited. This study aims to evaluate the feasibility of atrial STE ε analysis and the progression of atrial ε values as a function of post-operative time in children after pediatric cardiac surgery. Methods: 131 children (mean 1.69 ± 2.98; range 0.01–15.16 years) undergoing cardiac surgery were prospectively enrolled. Echocardiographic examinations were performed pre-operatively and at 3 different post-operative intervals: Time 1 (24–36 h), Time 2 (3–5 days), Time 3 (>5 days, before discharging). The right and left atrium longitudinal systolic contractile (Ct), Conduit (Cd), and Reservoir (R) ε were evaluated with a novel atrial specific software with both P- and R-Gating methods. One hundred and thirty-one age-matched normal subjects (mean 1.7 ± 3.2 years) were included as controls. Results: In all, 309 examinations were performed over the post-operative times. For each post-operative interval, all STE atrial ε parameters assessed were significantly lower compared to controls (all p < 0.0001). The lowest atrial ε values were found at Time 1, with only partial recovery thereafter (p from 0.02 to 0.04). All atrial ε values at discharge were decreased compared to the controls (all p < 0.0001). Significant correlations of the atrial ε values with cardio-pulmonary-bypass time, left and right ventricular ε values (p < 0.05), and ejection fraction (p < 0.05) were demonstrated. Conclusions: Atrial ε is highly reduced after surgery with only partial post-operative recovery in the near term. Our study additionally demonstrates that post-surgical atrial and ventricular ε responses correlated with each other.
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Nelle, M., C. Hoecker et O. Linderkamp. « Effects of packed red cell transfusion on pulmonary blood flow and right ventricular systolic time Intervals in neonates 176 ». Pediatric Research 40, no 3 (septembre 1996) : 544. http://dx.doi.org/10.1203/00006450-199609000-00199.
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Schaefer, Jacob J., Pavol Sajgalik, Sudhir S. Kushwaha, Lyle J. Olson, John M. Stulak, Bruce D. Johnson et John A. Schirger. « Left ventricle assist device pulsatility index at the time of implantation is associated with follow-up pulmonary hemodynamics ». International Journal of Artificial Organs 43, no 7 (27 janvier 2020) : 452–60. http://dx.doi.org/10.1177/0391398819899403.
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HeartMate II left ventricular assist device controllers provide data including pulsatility index, reflecting the relationship between pump function and hemodynamics. We propose that a higher pulsatility index at hospital discharge following implant may be associated with less vascular congestion and improved clinical outcomes. A retrospective analysis of 40 patients (age 59.2 ± 10.3 years) supported with the HeartMate II devices was conducted. Data revealed moderate Pearson correlations between pulsatility index at discharge and right atrial pressure, pulmonary artery systolic pressure, pulmonary artery diastolic pressure, mean pulmonary arterial pressure, and pulmonary capillary wedge pressure, respectively, post-surgery (median of 377 days), demonstrating a stronger relationship when analyzed for the EPC controller (n = 28) only (r = −.57, p < .01; r = −.38, p < .05; r = −.59, p < .01; r = −.47, p = .01 and r = −.53, p < .01, respectively). The pulsatility index derived from the EPC controller was associated with the significant risk of re-hospitalization within 1 and 2 years after the implantation of left ventricular assist device; hazard ratio = 0.557 with 95% confidence interval (0.315–0.983), p = .04 and hazard ratio = .579 (0.341–0.984), p = .04. A higher pulsatility index at discharge was associated with greater volume unloading, lower pulmonary pressures, and lower risk of all-cause re-hospitalizations within 1 and 2 years post-surgery. As such, pump-derived data may provide additional value in predicting left ventricular assist device hemodynamics.
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Bahler, R. C., et P. Martin. « Effects of loading conditions and inotropic state on rapid filling phase of left ventricle ». American Journal of Physiology-Heart and Circulatory Physiology 248, no 4 (1 avril 1985) : H523—H533. http://dx.doi.org/10.1152/ajpheart.1985.248.4.h523.
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Afterload, activation sequence, inotropism, and extent of shortening affect the time constant (T) of left ventricular (LV) isovolumic pressure decay, yet it is unknown if they modify peak lengthening velocity of the LV minor axis [(dD/dt)/D]. Accordingly, we studied their effects on (dD/dt)/D, measured by sonomicrometry, in nine anesthetized open-chest dogs during atrial pacing at 2 Hz. Afterload was increased 20-40 mmHg by 1) constricting the ascending aorta and 2) occluding the descending aorta for four beats. Activation was altered by right ventricular pacing. These interventions, plus constriction of venae cavae, were studied during four inotropic states. Aortic stenosis increased (dD/dt)/D (P less than 0.05), whereas occlusion of the descending aorta, vena caval constriction, and right ventricular pacing decreased (dD/dt)/D (P less than 0.05). Left atrial pressure was constant except during vena caval constriction. Alterations in inotropic state modified (dD/dt)/D (P less than 0.001). Extent of shortening and (dD/dt)/D were directly related (r = 0.80, P less than 0.001). Changes in (dD/dt)/D and T were inversely related (r = 0.70, P less than 0.001), and alterations in the interval from -dP/dtpeak to the end of rapid filling were directly related to changes in T (r = 0.75, P less than 0.001). We conclude that (dD/dt)/D can be modified by systolic and diastolic load perturbations, activation sequence, and inotropic interventions. These effects relate to changes in extent of shortening, time course of inactivation, or both.
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Tangney, Jared R., Stuart G. Campbell, Andrew D. McCulloch et Jeffrey H. Omens. « Timing and magnitude of systolic stretch affect myofilament activation and mechanical work ». American Journal of Physiology-Heart and Circulatory Physiology 307, no 3 (1 août 2014) : H353—H360. http://dx.doi.org/10.1152/ajpheart.00233.2014.
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Dyssynchronous activation of the heart leads to abnormal regional systolic stretch. In vivo studies have suggested that the timing of systolic stretch can affect regional tension and external work development. In the present study, we measured the direct effects of systolic stretch timing on the magnitude of tension and external work development in isolated murine right ventricular papillary muscles. A servomotor was used to impose precisely timed stretches relative to electrical activation while a force transducer measured force output and strain was monitored using a charge-couple device camera and topical markers. Stretches taking place during peak intracellular Ca2+ statistically increased peak tension up to 270%, whereas external work due to stretches in this interval reached values of 500 J/m. An experimental analysis showed that time-varying elastance overestimated peak tension by 100% for stretches occurring after peak isometric tension. The addition of the force-velocity relation explained some effects of stretches occurring before the peak of the Ca2+ transient but had no effect in later stretches. An estimate of transient deactivation was measured by performing quick stretches to dissociate cross-bridges. The timing of transient deactivation explained the remaining differences between the model and experiment. These results suggest that stretch near the start of cardiac tension development substantially increases twitch tension and mechanical work production, whereas late stretches decrease external work. While the increased work can mostly be explained by the time-varying elastance of cardiac muscle, the decreased work in muscles stretched after the peak of the Ca2+ transient is largely due to myofilament deactivation.
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Hatipoglu, Suzan, Peter Gatehouse, Sylvia Krupickova, Winston Banya, Piers Daubeney, Batool Almogheer, Cemil Izgi et al. « Reliability of pediatric ventricular function analysis by short-axis “single-cycle-stack-advance” single-shot compressed-sensing cines in minimal breath-hold time ». European Radiology 32, no 4 (29 octobre 2021) : 2581–93. http://dx.doi.org/10.1007/s00330-021-08335-5.
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Abstract Objectives Cardiovascular magnetic resonance (CMR) cine imaging by compressed sensing (CS) is promising for patients unable to tolerate long breath-holding. However, the need for a steady-state free-precession (SSFP) preparation cardiac cycle for each slice extends the breath-hold duration (e.g. for 10 slices, 20 cardiac cycles) to an impractical length. We investigated a method reducing breath-hold duration by half and assessed its reliability for biventricular volume analysis in a pediatric population. Methods Fifty-five consecutive pediatric patients (median age 12 years, range 7–17) referred for assessment of congenital heart disease or cardiomyopathy were included. Conventional multiple breath-hold SSFP short-axis (SAX) stack cines served as the reference. Real-time CS SSFP cines were applied without the steady-state preparation cycle preceding each SAX cine slice, accepting the limitation of omitting late diastole. The total acquisition time was 1 RR interval/slice. Volumetric analysis was performed for conventional and “single-cycle-stack-advance” (SCSA) cine stacks. Results Bland–Altman analyses [bias (limits of agreement)] showed good agreement in left ventricular (LV) end-diastolic volume (EDV) [3.6 mL (− 5.8, 12.9)], LV end-systolic volume (ESV) [1.3 mL (− 6.0, 8.6)], LV ejection fraction (EF) [0.1% (− 4.9, 5.1)], right ventricular (RV) EDV [3.5 mL (− 3.34, 10.0)], RV ESV [− 0.23 mL (− 7.4, 6.9)], and RV EF [1.70%, (− 3.7, 7.1)] with a trend toward underestimating LV and RV EDVs with the SCSA method. Image quality was comparable for both methods (p = 0.37). Conclusions LV and RV volumetric parameters agreed well between the SCSA and the conventional sequences. The SCSA method halves the breath-hold duration of the commercially available CS sequence and is a reliable alternative for volumetric analysis in a pediatric population. Key Points • Compressed sensing is a promising accelerated cardiovascular magnetic resonance imaging technique. • We omitted the steady-state preparation cardiac cycle preceding each cine slice in compressed sensing and achieved an acquisition speed of 1 RR interval/slice. • This modification called “single-cycle-stack-advance” enabled the acquisition of an entire short-axis cine stack in a single short breath hold. • When tested in a pediatric patient group, the left and right ventricular volumetric parameters agreed well between the “single-cycle-stack-advance” and the conventional sequences.
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Venkataraman, Pankaja S., Don A. Wilson, Roger E. Sheldon, Radhakrishna Rao et Michael K. Parker. « Effect of Hypocalcemia on Cardiac Function in Very-Low-Birth-Weight Preterm Neonates : Studies of Blood Ionized Calcium, Echocardiography, and Cardiac Effect of Intravenous Calcium Therapy ». Pediatrics 76, no 4 (1 octobre 1985) : 543–50. http://dx.doi.org/10.1542/peds.76.4.543.
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Traditionally, in infants, a serum calcium value less than 7.0 mg/dL is considered to impair cardiac function. In very-low-birth-weight infants, we studied the hypotheses that decline in serum calcium to 6.0 mg/dL (1) would not impair cardiac function and (2) ionized calcium would remain greater than 3.0 mg/dL. We also evaluated the effect of calcium infusion on cardiac function. We studied 15 normokalemic and normonatremic infants whose birth weights were 822 to 1,450 g and were less than 32 weeks' gestation. When serum calcium declined to less than 6.0 mg/dL, 18 mg/kg of calcium as 5% calcium gluconate was infused for 10 minutes. Serum total calcium concentration, blood ionized calcium concentration, ECG, and M-mode echocardiogram were obtained on entry into the study, when the infants were hypocalcemic, immediately after treatment with calcium, and eight hours after treatment. Ionized calcium values were calculated based on serum total calcium and serum protein, and corrected calcium values were calculated based on serum total calcium, serum albumin, and blood pH. In all infants, serum calcium value declined to less than 7.0 and in eight infants to less than 6.0 mg/dL. Assessment of heart rate, systolic blood pressure, ejection fraction, left ventricular systolic time interval, right ventricular systolic time interval, fiber shortening index, and left ventricular mean velocity of circumferential fiber shortening showed no significant alteration from baseline during hypocalcemia or in association with intravenous slow bolus infusion of 18 mg/kg of calcium. In association with a decline in serum total calcium to as low as 6.0 mg/dL, whole blood ionized calcium was maintained at more than 3.0 mg/dL. Serum total calcium and calculated ionized calcium values correlated significantly with measured blood ionized calcium concentrations; however, these measures were not reliable predictors of blood ionized calcium. We speculate that the hypoproteinemia and hypoalbuminemia noted in these infants may result in relative protection of the blood ionized calcium in these infants. We suggest that in neonates with wide ranges in gestation, serum protein, and blood pH levels, total serum calcium and calculated ionized calcium values may be poor measures of derangement of calcium metabolism. Decline in total serum calcium concentration to 6.0 mg/dL was not associated with impaired cardiac function, and slow bolus calcium infusion in these hypocalcemic very-low-birth-weight infants neither improved nor impaired cardiac function.
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Hata, T. « M-mode echocardiographic and electrocardiographic assessments of fetal right and left ventricular systolic time intervals during antenatal and early neonatal periods ». Journal of Obstetrics and Gynaecology 7, no 3 (1 janvier 1987) : 181–86. http://dx.doi.org/10.3109/01443618709068511.
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Meral Gunes, Adalet, Melike Sezgin Evim, Özlem Mehtap Bostan, Aysel Kaderli et Birol Baytan. « The Role of Cardiovascular T2*MRI and Tissue Doppler Measurement in Assesment of Cardiac Status in β-Thalassemia Major ». Blood 124, no 21 (6 décembre 2014) : 1363. http://dx.doi.org/10.1182/blood.v124.21.1363.1363.
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Abstract Introduction: Early detection of myocardial dysfunction and modification of treatment may prevent from progressing into the end stage heart failure and lethal arrhythmias in beta-thalassemia major (β-TM). T2* magnetic resonance imaging (MRI), a non-invasive technic determining iron accumulation in myocardium has been widespreadly used in these patients. Cardiac T2* MRI is not capable to evaluate cardiac functions but, indicates patients with risk for developing cardiac disease. Therefore, combining T2*MRI with tissue Doppler (TD) echocardiography, another technic defining both functional and structural evaluation of myocardium, could give a better information in evaluating the actual status of myocardium. The aim of this study was to evaluate cardiac status of thalassemics by using both T2*MRI and TD measurement. Methods: The study group includedpatientswith β-TM on regular transfusion and chelation program with preserved systolic function; ejection fraction > 55% and fractional shortening > 30% determined by conventional echocardiography. None of them had other organ dysfunctions adversely effecting cardiac functions. The control group was consisted of age and sex matched healthy persons. Serum ferritin levels were measured in both groups. In addition, TD measurements (S,E,A waves, time intervals; ejection time, total systolic time, isovolumetric accelaration time, isovolumetric contraction time, isovolumetric relaxation time and myocardial performance index) were obtained from three different regions of myocardium; septum, left and right ventricular posterior walls. T2* MRI was only determined in thalassemics. The study group was divided into two different subgroups according to serum ferritin level (low ferritin < 2500 ng/ml and high ferritin > 2500 ng/ml) and T2* MRI score (iron overloaded <20 ms and unloaded >20ms). The results obtained by TD within these subgroups were compared. TD measurements in thalassemics without cardiac iron overload were separately compared with the controls. Results: The study and control groups were consisted of 33 β-TM patients (16 girls/17 boys, mean age 18,7±7,7 years) and 37 healthy individuals (18 girls/19 boys, age 19,9±8,4 years), in respectively. Gender and age were similar (p>0,05). Systolic and diastolic functions by TD were found significantly impaired in thalassemics compared to the controls (p<0,05). S-lateral wave measurement showing early myocardial systolic function was more adversely effected in thalassemics (p<0,001). The patients' mean ferritin level was found 2242,3±2174,2 ng/ml (109-9843). Twelve patients (36,4%; 12/33) had high ferritin level and the rest (63,6%; 21/33) had low. T2*MRI and TD measurements did not differ in both subgroups (p>0.05). The mean T2*MRI score was 18,7±7,7 (7,3-29,8) ms in the study group. Twenty-one patients (63,6%; 21/33) had myocardial iron overload. Serum ferritin levels were similar between iron overloaded and unloaded groups (p>0.05). Both isovolumetric acceleration time of left ventricule and myocardial performance index (MPI-septal) showing systolic and diastolic functions were found significantly impaired in iron overloaded subgroup (p<0,05). There was negative correlation between MPI-septal and T2*MRI measurements in thalassemics (r:-0,343, p=0,050, fig 1). When we compared the velocity measurements (S,E,A waves) of iron unloaded thalassemics with the controls; only S wave velocity obtained from left ventricular wall was found significantly low (p<0,05). The time intervals measured from septum were found similar with the controls (p>0,05) but, the same measurements obtained from left and right ventricular posterior walls were significantly impaired (p<0,05). Figure 1: Correlation between Cardiac T2*MRI score and MPI-septal Figure 1:. Correlation between Cardiac T2*MRI score and MPI-septal Conclusions: This study showed that thalassemics with iron overload had significantly impaired TD measurements and MPI-septal index worsened when the mycardial iron load was increased (fig 1). Patients considered as iron unloaded according to T2*MRI result had left and right ventricular dysfunction determined by TD. Normal cardiac T2*MRI does not always associated with normal cardiac function. Therefore, we conclude that combining T2*MRI with TD measurements in evaluating cardiac status in β-TM, especially in patients with normal T2*MRI score, could lead to a better management of cardiac complications. Disclosures No relevant conflicts of interest to declare.
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Steen, T., B. M. Voss et O. A. Smiseth. « Influence of heart rate and left atrial pressure on pulmonary venous flow pattern in dogs ». American Journal of Physiology-Heart and Circulatory Physiology 266, no 6 (1 juin 1994) : H2296—H2302. http://dx.doi.org/10.1152/ajpheart.1994.266.6.h2296.
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In six open-chest anesthetized dogs we investigated the effect of heart rate (HR) on the relationship between left atrial pressure (LAP) and pulmonary venous flow (QPV). QPV was measured by ultrasonic transit time during volume loading and right atrial pacing. Consistent with previous studies, we found a negative correlation between LAP and mean flow rate during atrial systole divided by mean flow rate in the R-R interval. However, this relationship was shifted upward by tachycardia. The QPV maximum amplitude divided by mean flow rate in the R-R interval increased with loading but decreased with tachycardia. mean flow rate during ventricular systole divided by mean flow rate during the R-R interval increased with both loading and tachycardia. Regression coefficients for HR and LAP as predictors of these indexes were all significantly different from zero (P = 0.0001). We conclude that HR significantly influences the relationship between the QPV pattern and LAP. This could be a limitation of the pulmonary venous flow pattern as an indicator of left ventricular diastolic function.
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Nitsche, Christian, Andreas A. Kammerlander, Christina Binder, Franz Duca, Stefan Aschauer, Matthias Koschutnik, Amir Snidat et al. « Native T1 time of right ventricular insertion points by cardiac magnetic resonance : relation with invasive haemodynamics and outcome in heart failure with preserved ejection fraction ». European Heart Journal - Cardiovascular Imaging 21, no 6 (9 septembre 2019) : 683–91. http://dx.doi.org/10.1093/ehjci/jez221.
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Abstract Aims Increased afterload to the right ventricle (RV) has been shown to induce myocardial fibrosis at the RV insertion points (RVIPs). Such changes can be discrete but potentially detected by cardiac magnetic resonance (CMR) T1-mapping. Whether RVIP fibrosis is associated with prognosis in heart failure with preserved ejection fraction (HFpEF) is unknown. Methods and results We prospectively investigated 167 consecutive HFpEF patients, a population frequently suffering from post-capillary pulmonary hypertension, who underwent CMR including T1-mapping. About 92.8% also underwent right heart catheterization for haemodynamic assessment. Native T1 times were 995 ± 73 ms at the anterior and 1040 ± 90 ms at the inferior RVIP. By Spearman’s rank order testing, RVIP T1 times were significantly correlated with pulmonary artery pressure (mean PAP, r = 0.313 and 0.311 for anterior and inferior RVIP), pulmonary artery wedge pressure (r = 0.301 and 0.251) and right atrial pressure (r = 0.245 and 0.185; P for all <0.05). During a mean follow-up of 43.2 ± 22.6 months, 30 (18.0%) subjects died. By multivariable Cox regression, NTproBNP [Hazard ratio (HR) 2.105, 95% confidence interval (CI) 1.332–3.328; P = 0.001], systolic PAP (HR 1.618, 95% CI 1.175–2.230; P = 0.003), and native T1 time of the anterior RVIP (HR 1.659, 95% CI 1.125–2.445; P = 0.011) were significantly associated with outcome. Also, by Kaplan–Meier analysis, T1 times at the anterior RVIPs had a significant effect on survival (log-rank, P = 0.002). Conclusion Interstitial expansion of the anterior RVIP as detected by CMR T1-mapping reflects haemodynamic alterations, and is independently related with prognosis in HFpEF.
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Lisicka, Monika, Marta Skowrońska, Bartosz Karolak, Jan Wójcik, Piotr Pruszczyk et Piotr Bienias. « Heart Rate Variability Impairment Is Associated with Right Ventricular Overload and Early Mortality Risk in Patients with Acute Pulmonary Embolism ». Journal of Clinical Medicine 12, no 3 (17 janvier 2023) : 753. http://dx.doi.org/10.3390/jcm12030753.
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The association between heart rate variability (HRV) and mortality risk of acute pulmonary embolism (APE), as well as its association with right ventricular (RV) overload is not well established. We performed an observational study on consecutive patients with confirmed APE. In the first 48 h after admission, 24 h Holter monitoring with assessment of time‑domain HRV, echocardiography and NT‑proBNP (N-terminal pro‑B‑type natriuretic peptide) measurement were performed in all participants. We pre‑examined 166 patients: 32 (20%) with low risk of early mortality, 65 (40%) with intermediate–low, 65 (40%) with intermediate–high, and 4 (0.02%) in the high risk category. The last group was excluded from further analysis due to sample size, and finally, 162 patients aged 56.3 ± 18.5 years were examined. We observed significant correlations between HRV parameters and echocardiographic signs of RV overload. SDNN (standard deviation of intervals of all normal beats) correlated with echocardiography‑derived RVSP (right ventricular systolic pressure; r = −0.31, p = 0.001), TAPSE (tricuspid annulus plane systolic excursion; r = 0.21, p = 0.033), IVC (inferior vena cava diameter; r = −0.27, p = 0.002) and also with NT‑proBNP concentration (r = −0.30, p = 0.004). HRV indices were also associated with APE risk stratification, especially in the low-risk category (r = 0.30, p = 0.004 for SDNN). Univariate and multivariate analyses confirmed that SDNN values were associated with signs of RV overload. In conclusion, we observed a significant association between time‑domain HRV parameters and echocardiographic and biochemical signs of RV overload. Impaired HRV parameters were also associated with worse a clinical risk status of APE.
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Wainstein, Rodrigo V., Zion Sasson et Susanna Mak. « Frequency-dependent left ventricular performance in women and men ». American Journal of Physiology-Heart and Circulatory Physiology 302, no 11 (1 juin 2012) : H2363—H2371. http://dx.doi.org/10.1152/ajpheart.01125.2011.
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We aimed to determine whether sex differences in humans extend to the dynamic response of the left ventricular (LV) chamber to changes in heart rate (HR). Several observations suggest sex influences LV structure and function in health; moreover, this physiology is also affected in a sex-specific manner by aging. Eight postmenopausal women and eight similarly aged men underwent a cardiac catheterization-based study for force-interval relationships of the LV. HR was controlled by right atrial (RA) pacing, and LV +dP/d tmax and volume were assessed by micromanometer-tipped catheter and Doppler echocardiography, respectively. Analysis of approximated LV pressure-volume relationships was performed using a time-varying model of elastance. External stroke work was also calculated. The relationship between HR and LV +dP/d tmax was expressed as LV +dP/d tmax = b + mHR. The slope ( m) of the relationship was steeper in women compared with men (11.8 ± 4.0 vs. 6.1 ± 4.1 mmHg·s−1·beats−1·min−1, P = 0.01). The greater increase in contractility in women was reproducibly observed after normalizing LV +dP/d tmax to LV end-diastolic volume (LVVed) or by measuring end-systolic elastance. LVVed and stroke volume decreased more in women. Thus, despite greater increases in contractility, HR was associated with a lesser rise in cardiac output and a steeper fall in external stroke work in women. Compared with men, women exhibit greater inotropic responses to incremental RA pacing, which occurs at the same time as a steeper decline in external stroke work. In older adults, we observed sexual dimorphism in determinants of LV mechanical performance.
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Hu, Na, Na Yi et Huiqiong Yang. « Effect Evaluation of Cardiac Resynchronization Therapy in Elderly Patients with Heart Failure by Ultrasound Image under QuickOpt Algorithm ». Computational and Mathematical Methods in Medicine 2022 (7 juin 2022) : 1–10. http://dx.doi.org/10.1155/2022/8680446.
Texte intégralRésumé :
This research was aimed at analyzing the application value of echocardiography and QuickOpt algorithm in optimizing parameters of cardiac resynchronization therapy (CRT) in elderly patients with heart failure. 50 elderly patients who were diagnosed with chronic heart failure and underwent CRT were chosen as the research objects. According to the different optimization methods, the patients were divided into the echocardiography group and QuickOpt algorithm group, 25 cases in each group. The general data, optimized intervals, corresponding maximum aortic velocity time integrals (aVTIs), cardiac ultrasound indicators, and ventricular arrhythmia episodes of the patients in the two groups were analyzed. The results showed that there was no significant difference in the optimized sensed atrioventricular (SAV), paced atrioventricular (PAV), and ventricle to ventricle (VV) intervals and the corresponding aVTIs obtained by echocardiography and QuickOpt ( P > 0.05 ). The consistency analysis revealed that the aVTIs in the SAV, PAV, and VV intervals presented a good consistency ( P < 0.01 ), which were obtained by the echocardiography and QuickOpt functional optimization; the concordance correlation coefficient (CCC) in them was 96.16%, 98.03%, and 95.48%, respectively. The left ventricular ejection fraction (LVEF) showed an increasing trend over time in both groups, while the left ventricular end systolic volume (LVESV), left ventricular end diastolic volume (LVEDV), and morphological right ventricle (MRV) showed the downward trends over time, and the differences between two groups were not significant ( P > 0.05 ). For the premature ventricular contraction (PVC) of ventricular arrhythmia episodes, there was no significant difference between the two groups in log (PVCs) and log (PVC runs) ( P > 0.05 ). It was also found that both echocardiography and QuickOpt algorithm could improve the cardiac function of patients with heart failure significantly and reduce ventricular arrhythmia episodes and ventricular remodeling via optimized CRT; there was no difference in the improvement effect of the two optimization methods. However, echocardiography was inferior to QuickOpt algorithm in terms of time-consuming optimization in the intervals. This provided a reference for the clinical diagnosis and treatment of elderly patients with heart failure.
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Colebank, Mitchel J., et Naomi C. Chesler. « An in-silico analysis of experimental designs to study ventricular function : A focus on the right ventricle ». PLOS Computational Biology 18, no 9 (20 septembre 2022) : e1010017. http://dx.doi.org/10.1371/journal.pcbi.1010017.
Texte intégralRésumé :
In-vivo studies of pulmonary vascular disease and pulmonary hypertension (PH) have provided key insight into the progression of right ventricular (RV) dysfunction. Additional in-silico experiments using multiscale computational models have provided further details into biventricular mechanics and hemodynamic function in the presence of PH, yet few have assessed whether model parameters are practically identifiable prior to data collection. Moreover, none have used modeling to devise synergistic experimental designs. To address this knowledge gap, we conduct a practical identifiability analysis of a multiscale cardiovascular model across four simulated experimental designs. We determine a set of parameters using a combination of Morris screening and local sensitivity analysis, and test for practical identifiability using profile likelihood-based confidence intervals. We employ Markov chain Monte Carlo (MCMC) techniques to quantify parameter and model forecast uncertainty in the presence of noise corrupted data. Our results show that model calibration to only RV pressure suffers from practical identifiability issues and suffers from large forecast uncertainty in output space. In contrast, parameter and model forecast uncertainty is substantially reduced once additional left ventricular (LV) pressure and volume data is included. A comparison between single point systolic and diastolic LV data and continuous, time-dependent LV pressure-volume data reveals that any information from the LV substantially reduces parameter and forecast uncertainty, encouraging at least some quantitative data from both ventricles for future experimental studies.
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White, P. A., R. R. Chaturvedi, D. Shore, C. Lincoln, R. S. Szwarc, A. J. Bishop, P. J. Oldershaw et A. N. Redington. « Left ventricular parallel conductance during cardiac cycle in children with congenital heart disease ». American Journal of Physiology-Heart and Circulatory Physiology 273, no 1 (1 juillet 1997) : H295—H302. http://dx.doi.org/10.1152/ajpheart.1997.273.1.h295.
Texte intégralRésumé :
This study examines the accuracy of the conductance catheter technique and, in particular, parallel conductance [expressed as offset volume (Vc)] changes during the cardiac cycle in the human left ventricle. Two groups of patients were assessed: group 1, with an open atrial septal defect, and group 2, with an interventricular communication. In a subgroup, pre- and postoperative data were compared to assess the possible impact of shunting or anatomic considerations on our measurements. Vc is normally obtained by a saline-dilution technique previously described by Baan et al. [Vc(Baan); J. Baan, E. T. Van der velde, H. G. Debruin, G. J. Smeenk, J. Koops, A. D. Van Dijk, D. Temmerman, P. J. Senden, and B. Buis. Circulation 70: 812-823, 1984]. This does not take into account potential changes during the cardiac cycle. Four cardiac cycles were taken from the hypertonic saline washin and were divided into six equal isochrones between the maximum and minimum first derivatives of left ventricular pressure (dP/dtmax and dP/dtmin, respectively). The apparent ventricular volume was regressed against stroke volume for the corresponding cardiac cycle. The volume at the gamma-intercept corresponds to the Vc at each time interval [Vc(t)]. In group 1, there was a variation in Vc(t) during systole, but the temporal changes were quite small, on the order of 4.28% (SD = 5.18%) of total corrected end-diastolic volume (mean maximal variation of 2.60 ml). Furthermore, the value of Vc obtained at dP/dtmax was not significantly different from that obtained at dP/dtmin. For group 2 as a whole, mean Vc(Baan) did not change significantly with ventricular septal defect closure (preoperative, 8.85 +/- 11.1 ml; postoperative, 9.82 +/- 11.84 ml). Group 2 children also exhibited a systolic cyclical variation in Vc(t) similar to group 1. Finally, Vc(t) as a percentage of end-diastolic volume was no different when group 1 and group 2 were compared. We conclude that in the left ventricle, even in the presence of a left-to-right shunt, there is a small but insignificant difference in parallel conductance during ventricular ejection. The magnitude of this cyclical change does not preclude ventricular volume measurement in congenital heart disease by the conductance catheter technique.
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Perepeka, Eugene O., et Borys B. Kravchuk. « Results of Using Various Conduction System Pacing Options in Patients with Bradyarrhythmia ». Ukrainian Journal of Cardiovascular Surgery 30, no 4 (26 décembre 2022) : 94–103. http://dx.doi.org/10.30702/ujcvs/22.30(04)/pk064-94103.
Texte intégralRésumé :
Chronic right ventricular myocardial pacing causes an asynchronous pattern of left ventricular activation, reduces left ventricular ejection fraction (LVEF), and may be associated with worsening of clinical outcomes in the long term. Although with the emergence of algorithms that minimize ventricular pacing it became possible to reduce the percentage of paced complexes in patients with sinus node dysfunction, permanent ventricular pacing is still inevitable in patients with high-degree atrioventricular (AV) block. The use of permanent conduction system pacing is a promising method for preserving the physiological activation of the ventricular myocardium and preventing the development of heart failure due to ventricular dyssynchrony.
The aim. To analyze the immediate and long-term results of the use of conduction system pacing in patients with indications for permanent ventricular pacing.
Materials and methods. This study included 18 patients with indications for permanentventricular pacing who were operated at the National Amosov Institute of Cardiovascular Surgery of the National Academy of Medical Sciences of Ukraine in the period from 01/01/2013 to 12/31/2022, in whom permanent conduction system pacing was used. There were 17 patients with bradyarrhythmias, of these 16 (88%) suffered from high-degree AV block (including 1 patient with Frederick’s syndrome and 1 (5%) patient with atrial ϐibrillation with slow ventricular response) and 1 (5%) patient with ischemic cardiomyopathy with left bundle branch block and ϐirstdegree AV block with indications for cardiac resynchronization therapy. The mean age of the patients was 55 ± 16 years (8 men, 10 women), LVEF at the time of the intervention was 56.42 ± 9.13 %, end diastolic volume 130.2 ± 23.8 ml, end systolic volume 55.1 ± 17.7 ml, diameter of the left atrium 4.01 ± 0.6 cm. The average QRS width before implantation was 116.5 ± 27.7 ms. In 6 (33%) patients, a special delivery system (С304-L69, Medtronic in 1 patient [5%], C315HIS in 5 [27%] patients) and 4.1F active ϐixation lead Medtronic 3830 Select Secure (69 or 74 cm) were used; in other cases (66%) standard 6F leads with active ϐixation and a lumen for a stylet without a delivery system were used.
Results. The average follow-up period after implantation of pacemaker was 36.35 ± 29.65 months. During the observation period, LVEF was 57.07 ± 5.38 %, end diastolic volume111.5 ± 18.09 ml, end systolic volume 49.5 ± 13.4 ml, diameter of the left ventricle 3.9 ± 0.5 cm. The mean duration of paced QRS was 119.1 ± 10.09 ms. In 6 patients (33%), it was possible to demonstrate a change in the QRS width when the amplitude of ventricular stimulation was reduced, with 2 variants of transitions: 1) 4 (22%) patients with a transition from non-selective His bundle pacing (NSHBP) to selective His bundle pacing (SHBP), in 2 (11%) of these patients with a transition from SHBP with correction of right bundle branch block (RBBB) to SHBP without correction of RBBB, and then loss of capture of the myocardium of the ventricles; 2) 2 patients (11%) with a transition from NSHBP to myocardial septal ventricular pacing and further with a decrease in amplitude to the loss of capture of the myocardium of the ventricles. One (5%) patient with complete heart block had permanent non-selective left bundle branch area pacing. The other 11 (61%) patients met the criteria for parahisian pacing without visible transitions with a change in the amplitude of ventricular pacing. The average global longitudinal strain was -17.6 ± 2.7 %. The average interval from the stimulus to the peak of the R-wave in lead V6, which indicated the time of left ventricular activation, was 73.2 ± 8.7 ms. Pacing parameters were standardly set according to the primary indications, but with correction of the amplitude of ventricular stimulation relative to the thresholds of pacing of the conduction system. AV delay was corrected for the latency from the stimulus to the onset of the QRS in SHBP or for the duration of the “pseudodelta” wave in NSHBP which in both cases was the duration of the H-V interval. There were no complications in the acute or long-term postoperative period.
Conclusions. Conduction system pacing is a challenge in the practice of cardiologist for treating life-threatening bradyarrhythmias and heart failure, but at the same time it is a safe method that provides physiological electrical and mechanical activation of the myocardium of the ventricles, that allows to effectively avoid the consequences of dyssynchrony due to permanent myocardial ventricular pacing.
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Orlov, O. S., A. Asfour, A. A. Bogdanova, D. Yu Shchekochikhin, A. S. Akselrod, A. P. Nesterov et D. A. Andreev. « Predictors of tachycardia-induced cardiomyopathy in patients with first-time decompensation of chronic heart failure with reduced left ventricular ejection fraction of nonischemic etiology and persistent atrial tachyarrhythmia ». Kardiologiia 62, no 11 (30 novembre 2022) : 56–62. http://dx.doi.org/10.18087/cardio.2022.11.n2262.
Texte intégralRésumé :
Aim To identify possible predictors of tachycardia-induced cardiomyopathy (TICMP) in patients with newly developed decompensated chronic heart failure (CHF) of nonischemic origin with reduced left ventricular ejection fraction (LV EF) and with persistent atrial tachyarrhythmias. Material and methods This study included 88 patients with newly developed decompensated CHF of nonischemic origin with reduced LV EF and persistent atrial tachyarrhythmias. Resting 12-lead electrocardiography (EGC) and transthoracic echocardiography (EchoCG) were performed upon admission and following the electrical impulse therapy for all patients. Also, 24-h ECG monitoring was performed to confirm sinus rhythm stability. After recovery of sinus rhythm, outpatient monitoring was performed for three months, including repeated EchoCG to evaluate the dynamics of heart chamber dimensions and LV EF. Results The patients were divided into two groups based on the increase in LV EF: 68 responders (TICMP patients with a LV EF increase by >10%) and 20 non-responders (patients with an increase in LV EF by <10% during 3 months following the sinus rhythm recovery). According to results of the baseline EchoCG, LV EF did not significantly differ in the two subgroups (TICMP, 40±8.3 %, 18–50 % and non-responders, 38.55±7.9 %, 24–50 %); moreover, the incidence of cases with LV EF <30% did not differ either (9 patients TICMP and 2 non-responders, р=1.0). TICMP patients compared to non-responders, had significantly smaller left atrial dimensions (4.53±1.14 (2–7) cm and 5.68±1.41 (4–8) cm, р=0.034; 80.8±28.9 (27–215) ml and 117.8±41.3 (46–230) ml, р=0.03, respectively) and left ventricular end-systolic volume (ESV) (67.7±33.1 (29–140) ml and 104.5±44.7 (26–172) ml, р=0.02, respectively). The effect of major EchoCG parameters on the probability of TICMP development was assessed by one-factor and multifactor regression analyses with adjustments for age and sex. The probability of TICMP increased with the following baseline EchoCG parameters: end-diastolic volume (EDV) <174 ml [odd ratio (OR), 0.115, 95 % confidence interval (CI): 0.035–0.371], ESV <127 ml [OR, 0.034, 95 % CI: 0.007–0.181], left atrial volume <96 ml [OR, 0.08 , 95 % CI: 0.023–0.274], right ventricular dimension <4 cm [OR, 0.042 , 95 % CI: 0.005–0.389].Conclusion Among patients with newly developed decompensation of CHF with reduced LV EF of non-ischemic origin and persistent atrial arrhythmias, TICMP was detected in 72 % of patients. The probability of TICMP did not depend on baseline EF and duration of arrhythmias, but increased with the following baseline EchoCG parameters: EDV< 174 ml, ESV< 127 ml, left atrial volume <96 ml, right ventricular dimension <4 cm. The multifactorial analysis showed that a right atrial volume <96 ml is an independent predictor for the development of TICMP.
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Zhuang, Wei, Guili Lian, Bangbang Huang, Apang Du, Genfa Xiao, Jin Gong, Changsheng Xu, Huajun Wang et Liangdi Xie. « Pulmonary arterial hypertension induced by a novel method : Twice-intraperitoneal injection of monocrotaline ». Experimental Biology and Medicine 243, no 12 (août 2018) : 995–1003. http://dx.doi.org/10.1177/1535370218794128.
Texte intégralRésumé :
Pulmonary arterial hypertension (PAH) in humans manifests as a chronic process. However, PAH induced by high-dose monocrotaline (MCT) in animals occurs as a subacute process. To establish a chronic PAH model, rats were randomly divided into three groups, control (ctrl), single injection (SI), and twice injection (TI) groups. Rats in the SI group received a single intraperitoneal injection of 40 mg/kg MCT on day 0. Rats in the TI group received twice injections of 20 mg/kg MCT on days 0 and 7. Survival percentage, characteristic changes of pulmonary arterial variables, and right ventricular features were evaluated. Thirty-five days after the first MCT injection, survival percentage in TI group was higher than that in the SI group. The mean pulmonary arterial pressure (mPAP), right ventricular hypertrophy index (RVHI), pulmonary vascular remodeling, serum tumor necrosis factor α (TNFα), and interleukin-6 (IL-6) were higher either in SI or in TI 28 and 35 days after the first MCT injection. The rats in the SI and TI groups exhibited higher right ventricle end diastolic diameter (RVEDD) and lower adjusted pulmonary artery acceleration time (PAAT/HR), tricuspid annular plane systolic excursion (TAPSE), cardiac output (CO) and right ventricle fractional shortening (RVFS) when compared with controls. However, mPAP, RVHI, TAPSE, PAAT/HR, CO, TNFα, and IL-6 were lower and RVEDD were higher in the TI group than in the SI group. Pulmonary macrophage infiltration and right ventricle (RV) fibrosis were lower in TI than SI groups. The cardiomyocyte cross-sectional area and the beta myosin heavy chain (MYH7) mRNA level of RV were lower in TI than SI, whereas alpha myosin heavy chain (MYH6) was increased. These results show that two intraperitoneal injections of 20 mg/kg MCT with seven days interval could induce a model similar to chronic PAH with increased survival percentage in rats. Impact statement We demonstrated previously that a single intraperitoneal injection of 40 mg/kg MCT produced a subacute, not chronic, PAH model in rats, and the short survival periods of these rats did not represent adequately the chronic PAH seen in humans. To overcome this limitation, in this study, the single dose of 40 mg/kg MCT was divided into twice injections of 20 mg/kg with an interval of seven days. This modified administration of MCT produced an animal model much more similar to chronic PAH with prolonged survival and characteristic changes of structures and function in pulmonary arteries and right ventricles.
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Сherepanova, N. A., I. S. Mullova, A. R. Kiselev, T. V. Pavlova, S. M. Khokhlunov et D. V. Duplyakov. « Thrombolytic Therapy in Normotensive Patients with Pulmonary Embolism (Data from the Retrospective Study) ». Rational Pharmacotherapy in Cardiology 16, no 5 (4 novembre 2020) : 742–48. http://dx.doi.org/10.20996/1819-6446-2020-10-13.
Texte intégralRésumé :
Background. The thrombolytic therapy is absolutely recommended for patients in shock or hypotension because the benefits are clearly outweighing the risks. However, in hemodynamically stable patients, including those with acute right ventricular dysfunction and/or myocardial damage, thrombolysis has a significantly lower evidence level.Aim. To study the criteria based on which doctors decide to conduct thrombolytic therapy in normotensive patients in real clinical practice according to the retrospective data.Material and methods. A single-center retrospective cohort study analyzed medical records of patients hospitalized in 2006-2017 with a verified diagnosis of pulmonary embolism (PE) and who had a systolic blood pressure >90 mm Hg at the time of admission.Results. The present study population included 299 patients with a verified diagnosis of PE from 2006 to 2017 years. Patients were divided into two groups: with thrombolysis (group 1) and without thrombolysis (group 2). Logistic regression analysis showed that age younger than 60 years, the presence of varicose veins of the lower extremities, skin cyanosis, syncope in the debut of PE were independent clinical factors that significantly influence the doctor's decision to perform thrombolysis. Increased troponin I, right ventricular dysfunction, and the severity of PE according to the PESI score showed no significant impact on this decision. In-hospital mortality in the group 2 was 1.9% (5 patients), while there were no deaths in the group 1. But the analysis of the association of thrombolysis with survival was difficult to perform due to the low incidence of deaths and the small number of patients in the group with thrombolysis (odds ratio 0.34; 95% confidence interval 0.03-8.18; р=0.856). No major bleeding was registered in any group.Conclusion. We were not able to clearly identify independent clinical or instrumental factors that influence the decision to perform thrombolysis in patients with PE outside the framework of evidence-based medicine. Further research is needed.
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Degenhardt, Jan, Meike Reinold, Christian Enzensberger, Aline Wolter, Andrea Kawecki, Thomas Kohl, Oliver Graupner et al. « Short-Time Impact of Laser Ablation of Placental Anastomoses on Myocardial Function in Monochorionic Twins with Twin-to-Twin Transfusion Syndrome ». Ultraschall in der Medizin - European Journal of Ultrasound 38, no 04 (2 septembre 2015) : 403–10. http://dx.doi.org/10.1055/s-0035-1553405.
Texte intégralRésumé :
Abstract Purpose To evaluate pre- and post-procedure myocardial function in monochorionic twins with TTTS who underwent laser ablation of placental anastomoses using pulsed wave tissue Doppler imaging (pw TDI). Materials and Methods 20 monochorionic twin gestations with TTTS were included and underwent laser ablation at our center between 2011 and 2014. Prior to and after the intervention, cardiac function was assessed by measuring the mitral annular plane systolic excursion (MAPSE), the tricuspid annular plane systolic excursion (TAPSE), Tei index, isovolumetric contraction time (ICT), ejection time (ET), isovolumetric relaxation time (IRT) for the left ventricle in pulsed wave Doppler (pw D) ultrasound as well as ICT, ET, IRT and Tei index in pw TDI for the left and right ventricle. E-, A-, E´- and A´-wave peak velocity and the systolic downward motion (S´) were measured for both ventricles and the E/A, E/E´ and E´/A´ ratios were calculated. In a mean of 1.3 (SD 0.6) days after laser ablation, this measurement protocol was repeated. Results Pre-intervention recipients had longer ICT, ET and IRT in pw D and pw TDI compared to donors not reaching statistical significance for most parameters. Statistically significant were prolonged ICT in pw D (p 0.01) and ET (p 0.01) in pw TDI in recipients. In donor fetuses preoperative myocardial function did not differ significantly from postoperative myocardial function except in increased left ventricular ejection time of the left ventricle in pw TDI (p 0.04) and an increased E´/A´ratio (p 0.01). After laser coagulation, myocardial function was slightly altered in recipients as ICT and IRT shortened and Tei indices decreased but only reaching statistical significance in shortened IRTs in pw TDI for both ventricles. Conclusion Laser ablation of placental anastomoses in TTTS might influence myocardial function in the postoperative period. Shortened IRT intervals may reflect an improvement of diastolic function in recipients.
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Nield, Lynne E., Brian W. McCrindle, Desmond J. Bohn, Lori J. West, Jhon G. Coles, Robert M. Freedom et Lee N. Benson. « Outcomes for children with cardiomyopathy awaiting transplantation ». Cardiology in the Young 10, no 4 (juillet 2000) : 358–66. http://dx.doi.org/10.1017/s1047951100009665.
Texte intégralRésumé :
AbstractObjectiveTo determine factors associated with outcomes after listing for transplantation in children with cardiomyopathies.BackgroundChildhood cardiomyopathies form a heterogeneous group of diseases, and in many, the prognosis is poor, irrespective of the etiology. When profound heart failure develops, cardiac transplantation can be the only viable option for survival.MethodsWe included all children with cardiomyopathy listed for transplantation between 12/89 and 4/98 in this historical cohort study.ResultsWe listed 31 patients, 15 male and 16 female, 27 with dilated and 4 with restrictive cardiomyopathy, for transplantation. The median age at listing was 5.7 years, with a range from fetal life to 17.8 years. Transplantation was achieved in 23 (74%), with a median interval from listing of 54 days, and a range from zero to 11.4 years. Of the patients, 14 were transplanted within 30 days of listing. Five patients (16%) died before transplantation. Within the Canadian algorithm, one of these was in the third state, and four in the fourth state. One patient was removed from the list after 12 days, having recovered from myocarditis, and two remain waiting transplantation after intervals of 121 and 476 days, respectively. Patients who died were more likely to be female (5/5 vs. 11/26; p=0.04) and to have been in the third or fourth states at listing (5/5 vs. 15/26; p=0.04). The use of mechanical ventricular assistance, in 10 patients, was not a predictor of an adverse outcome. While not statistically significant, survival to transplantation was associated with treatment using inhibitors of angiotensin converting enzyme, less mitral regurgitation, a higher mean ejection fraction and cardiac index, and lower right ventricular systolic pressure.ConclusionsChildren with cardiomyopathy awaiting transplantation have a mortality of 16% related to their clinical state at the time of listing.
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Shirokov, N. E., E. I. Yaroslavskaya, D. V. Krinochkin et N. A. Osokina. « Hidden systolic dysfunction of the right ventricle in patients with increased pulmonary vascular resistance 3 months after COVID-19 pneumonia ». Kardiologiia 62, no 3 (31 mars 2022) : 16–20. http://dx.doi.org/10.18087//cardio.2022.3.n1743.
Texte intégralRésumé :
Aim To study the relationship of echocardiographic right ventricular (RV) structural and functional parameters and indexes of pulmonary vascular resistance (PVR) in patients 3 months after COVID-19 pneumonia.Material and methods This cross-sectional, observational study included 96 patients aged 46.7±15.2 years. The inclusion criteria were documented diagnosis of COVID-19-associated pneumonia and patient’s willing to participate in the observation. Patients were examined upon hospitalization and during the control visit (at 3 months after discharge from the hospital). Images and video loops were processed, including the assessment of myocardial longitudinal strain (LS) by speckle tracking, according to the effective guidelines. The equation [tricuspid regurgitation velocity/ time-velocity integral of the RV outflow tract × 10 + 0.16] was used to determine PRV. Patients were divided into group 1 (n=31) with increased PRV ≥1.5 Wood units and group 2 (n=65) with PRV <1.5 Wood units.Results At baseline, groups did not differ in main clinical functional characteristics, including severity of lung damage by computed tomography (32.7±22.1 and 36.5±20.4 %, respectively. р=0.418). Echocardiographic linear, planimetric and volumetric parameters did not significantly differ between the groups. In group 1 at the control visit, endocardial LS of the RV free wall (FW) (–19.3 [–17.9; –25.8] %) was significantly lower (р=0.048) than in group 2 (–23.4 [–19.8; –27.8] %), and systolic pulmonary artery pressure (sPAP) according to C. Otto (32.0 [26.0; 35.0] mm Hg and 23.0 [20.0; 28.0] mm Hg) was significantly higher than in group 2 (р<0.001). According to the logistic regression, only endocardial RV FW LS (odds ratio, OR, 0.859; 95 % confidence interval, CI, 0.746–0.989; р=0.034) and sPAP (OR, 1.248; 95 % CI, 1.108–1405; р<0.001) were independently related with the increase in PVR. Spearman correlation analysis detected a moderate relationship between PVR and mean PAP according to G. Mahan (r=0.516; p=0.003) and between PVR and the index of right heart chamber functional coupling with the PA system (r=–0.509; p=0.007) in group 1 at the control visit.Conclusion In patients 3 months after COVID-19 pneumonia, hidden RV systolic dysfunction defined as depressed endocardial RV FW LS to -19.3% is associated with increased PVR ≥1.5 Wood units.
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Ilov, N. N., D. R. Stompel, S. A. Boytsov, O. V. Palnikova et A. A. Nechepurenko. « Perspectives on the Use of Transthoracic Echocardiography Results for the Prediction of Ventricular Tachyarrhythmias in Patients with Non-ischemic Cardiomyopathy ». Rational Pharmacotherapy in Cardiology 18, no 3 (6 juillet 2022) : 251–60. http://dx.doi.org/10.20996/1819-6446-2022-06-01.
Texte intégralRésumé :
Aim. To perform a comparative analysis of indicators of transthoracic echocardiography (TE), to establish echocardiographic predictors and their predictive role in the occurrence of stable ventricular tachyarrhythmia (VT) paroxysms in patients with nonischemic chronic heart failure (HF) and cardioverter-defibrillator (ICD) implanted for primary prevention of sudden cardiac death.Material and Methods. A prospective study was carried out, which included 166 patients with nonischemic HF at the age of 54 (49; 59) years with the left ventricle ejection fraction (LV EF) ≤35% and an ICD implanted. The observation time was 24 months. The primary endpoint was the first-ever stable paroxysm of VT (lasting for ≥30 seconds), detected in the «monitor» zone of VT, or paroxysm of VT, which required ICD therapy. A total of 34 TE indicators were evaluated. Chi-square, Fischer, Manna-Whitney, single-factor logistic regression (LR), and multi-factor LR were used for data processing and analysis and for predictive modelling. Model accuracy was estimated using 4 metrics: ROC curve area (AUC), sensitivity, specificity and diagnostic efficiency.Results. During the two-year observation, 32 patients (19.3%) had a primary endpoint. The average time of occurrence of a stable VT episode was 21.6±0.6 months (95% confidence interval [CI] 20.5-22.8 months). The value of LV end-systolic dimension was the only parameter independently associated with VT (odds ratio 2.8 per unit increase, 95% CI 1.04-7.5; p=0.042). The complex analysis of echocardiographic indicators made it possible to identify 5 factors with the greatest predictive potential, which are linearly and nonlinearly related to occurrence of VT. These included the LV end-diastolic and end-systolic volumes, LV mass, index of relative LV wall thickness, upper-lower size of the right atrium. The metrics of the best predictive model were: AUC – 0.71 0.069 with 95% CI 0.574-0.843; specificity 50%, sensitivity 90.9%; diagnostic efficiency 57.1%.Conclusion. The study made it possible to evaluate the possibilities of the results of TE in predicting the probability of VT occurrence in patients with nonischemic HF and reduced LV EF. Predictive indicators have been identified that can be used to stratify the arrhythmic risk in the exposed cohort of patients.
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van den Bosch, Eva, Judith A. A. E. Cuypers, Saskia E. Luijnenburg, Nienke Duppen, Eric Boersma, Ricardo P. J. Budde, Gabriel P. Krestin et al. « Ventricular response to dobutamine stress cardiac magnetic resonance imaging is associated with adverse outcome during 8-year follow-up in patients with repaired Tetralogy of Fallot ». European Heart Journal - Cardiovascular Imaging 21, no 9 (9 octobre 2019) : 1039–46. http://dx.doi.org/10.1093/ehjci/jez241.
Texte intégralRésumé :
Abstract Aims The aim of this study was to evaluate the possible value of dobutamine stress cardiac magnetic resonance imaging (CMR) to predict adverse outcome in Tetralogy of Fallot (TOF) patients. Methods and results In previous prospective multicentre studies, TOF patients underwent low-dose dobutamine stress CMR (7.5 µg/kg/min). Subsequently, during regular-care patient follow-up, patients were assessed for reaching the composite endpoint (cardiac death, arrhythmia-related hospitalization, or cardioversion/ablation, VO2 max ≤65% of predicted). A normal stress response was defined as a decrease in end-systolic volume (ESV) and increase in ejection fraction. The relative parameter change during stress was calculated as relative parameter change = [(parameterstress − parameterrest)/parameterrest] * 100. The predictive value of dobutamine stress CMR for the composite endpoint was determined using time-to-event analyses (Kaplan–Meier) and Cox proportional hazard analysis. We studied 100 patients [67 (67%) male, median age at baseline CMR 17.8 years (interquartile range 13.5–34.0), age at TOF repair 0.9 years (0.6–2.1)]. After a median follow-up of 8.6 years (6.7–14.1), 10 patients reached the composite endpoint. An abnormal stress response (30% vs. 4.4%, P = 0.021) was more frequently observed in composite endpoint patients. Also in endpoint patients, the relative decrease in right ventricular ESV decreased less during stress compared with the patients without an endpoint (−17 ± 15 vs. −26 ± 13 %, P = 0.045). Multivariable analyses identified an abnormal stress response (hazard ratio 10.4; 95% confidence interval 2.5–43.7; P = 0.001) as predictor for the composite endpoint. Conclusion An abnormal ventricular response to dobutamine stress is associated with adverse outcome in patients with repaired TOF.