Academic literature on the topic 'Right ventricular systolic time interval'

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Journal articles on the topic "Right ventricular systolic time interval"

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Zatko, F. J., P. Martin, and 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 (March 1, 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, and 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 (December 1999): 2703–6. http://dx.doi.org/10.1097/00003246-199912000-00017.

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Bodh, Deepti, Mozammel Hoque, and Abhishek Chandra Saxena. "Echocardiographic study of healthy Indian Spitz dogs with normal reference ranges for the breed." Veterinary World 12, no. 6 (June 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, and 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 (March 4, 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, and Cynthia Holland. "Right ventricular systolic time intervals: Comparison of echocardiographic and Doppler-derived values." American Heart Journal 112, no. 1 (July 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, and Patricia A. Reynolds. "Effect of sampling site on Doppler-derived right ventricular systolic time intervals." American Journal of Cardiology 65, no. 13 (April 1990): 950–52. http://dx.doi.org/10.1016/0002-9149(90)91452-c.

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Her, Charles, Hideo Koike, and 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 (May 2009): 460–65. http://dx.doi.org/10.1097/shk.0b013e31818ba1f4.

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Nguyen Quoc, Thai, and 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 (June 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, and 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 (October 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, and 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 (November 10, 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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Dissertations / Theses on the topic "Right ventricular systolic time interval"

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ALBERTI, ELENA. "EVALUATION OF PULMONARY ARTERY STIFFNESS IN ASTHMA AFFECTED HORSES." Doctoral thesis, Università degli Studi di Milano, 2022. http://hdl.handle.net/2434/916663.

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The present research evaluated Pulmonary Artery Stiffness (PAS) and right ventricular systolic time intervals (RVSTIs) in horses with mild/moderate (MEA) and severe (SEA) equine asthma and in healthy horses. In human medicine, PAS is a pulsed-wave (PW) Doppler echocardiographic parameter useful in assessing an increase in pulmonary artery stiffness due to remodeling of the vessel wall caused by chronic diseases. Moreover, PAS in humans is used as an early indicator of pulmonary hypertension. RVSTIs, such as acceleration time (AT), ejection time (ET) and acceleration time index (AT/ET), are other PW Doppler parameters useful for the evaluation of changes in the pulmonary vascular bed. Like human asthma, equine asthma is able to induce remodeling of the pulmonary artery wall even in horses, leading to a decreased pulmonary artery elasticity and consequently pulmonary hypertension. Therefore, it is conceivable that PAS could be a useful parameter also in horses. However, there are no studies on PAS in veterinary medicine. The aims of this research were: to assess feasibility of PAS in horses, to evaluate possible influence of age, bodyweight, sex and heart rate on PAS and RVSTIs, to investigate possible differences between healthy, MEA and SEA horses regarding those parameters, to evaluate possible correlation between PAS and RVSTIs and ratio of pulmonary artery diameter to aorta diameter (PAD/AOD) and to determine PAS and AT cut-off values for diagnosis of SEA. Echocardiographic examination and PW Doppler of the pulmonary flow were performed in 23 MEA affected horses, 15 SEA affected horses and 15 healthy horses. Results demonstrated that PAS can been measured consistently in horses and that, as well as RVSTIs, it is not influenced by age, bodyweight, sex and heart rate. Moreover, a significant higher PAS and lower RVSTIs were detected in SEA affected horses compared to healthy subjects and MEA affected ones. In addition, considering the whole sample, a positive correlation between PAS and PAD/AOD and a negative correlation between AT or AT/ET and PAD/AOD were found. These findings, in association with several similarities between equine asthma and human asthma, suggest that these parameters could be correlated to pulmonary pressure even in horses. Finally, this study determined that a PAS value of 8.18 kHz/sec and a AT value of 0.202 sec are the best cut-off values, with a very high sensitivity (PAS: 93.33%; AT: 86.67%) and specificity (PAS: 86.84%; AT: 89.47%), for the diagnosis of SEA.
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Book chapters on the topic "Right ventricular systolic time interval"

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Chew, Michelle S. "Right ventricular function." In Oxford Textbook of Advanced Critical Care Echocardiography, edited by Anthony McLean, Stephen Huang, and Andrew Hilton, 119–32. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198749288.003.0008.

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The right ventricle (RV) has historically been given less importance than the left. There are important anatomical differences, including several intracardiac structures that may complicate echocardiographic assessments. The right heart is sensitive to changes in pressure and its function is affected by common interventions in critical care such as fluid loading and positive pressure ventilation. Right and left ventricular functions are inextricably linked, and both systolic and diastolic ventricular interdependence occur. The echocardiographic examination of the RV includes an assessment of size and dimensions, systolic and diastolic function, estimation of intracardiac and pulmonary pressures. These should be interpreted in the context of the clinical interventions that the patient was subjected to at the time of imaging, as well as left ventricular function. RV failure is associated with poorer outcomes in several disease states including congestive cardiac failure and acute myocardial infarction. In critically ill patients, acute respiratory distress syndrome (ARDS) has significant implications for right heart function, where there is a necessary balance between respiratory mechanics and haemodynamics.
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Slama, Michel, and Julien Maizel. "Pulmonary hypertension." In Oxford Textbook of Advanced Critical Care Echocardiography, edited by Anthony McLean, Stephen Huang, and Andrew Hilton, 133–40. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198749288.003.0009.

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Acute pulmonary hypertension (PH) is common in ICU patients, particularly in septic shock, acute respiratory distress syndrome (ARDS), pulmonary embolism, and cardiac heart failure. Although many patients with lung diseases develop chronic PH, primary pulmonary arterial hypertension is less frequent, but still can be observed in ICU patients. Pulmonary arterial pressure (PAP) can be assessed using continuous-wave Doppler with the help of colour Doppler. Tricuspid regurgitation can be recorded with systolic as well as mean PAP estimated respectively from maximal and mean velocity of flow. Excellent correlations with invasive methods were found despite PAP increasing with age, body mass, and arterial hypertension. Pulmonary regurgitation is useful to estimate diastolic, mean, and systolic PAP. The right ventricular outflow tract flow can be used to rule out or rule in PH. Also, isovolumic contraction time on tissue Doppler imaging (TDI) tricuspid annular velocities allows prediction of systolic PAP (sPAP). Chronic and acute PH are usually associated with dilation of the right ventricle, atrium, and inferior vena cava as well as paradoxical septal movement. Right ventricular hypertrophy, right ventricular systolic function, and the size of the left ventricle can help to differentiate chronic from acute PH.
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Haydock, Paul M., and Peter J. Cowburn. "Cardiac resynchronization therapy." In Oxford Textbook of Heart Failure, edited by Andrew L. Clark, Roy S. Gardner, and Theresa A. McDonagh, 737–56. Oxford University Press, 2022. http://dx.doi.org/10.1093/med/9780198766223.003.0060.

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This chapter examines cardiac resynchronization therapy (CRT), or biventricular pacing (BVP), which is now well established as a therapeutic option for selected, symptomatic patients with heart failure due to left ventricular systolic dysfunction and reduced ejection fraction (HFrEF) and a prolonged QRS interval. Numerous well-designed trials, in conjunction with more than a decade of clinical experience, have demonstrated the efficacy of CRT in improving symptoms, reducing hospitalizations, and prolonging survival, when combined with optimal medical therapy in this patient group. CRT improves electromechanical dyssynchrony and maximizes the efficiency of the cardiac contraction sequence, leading to an acute haemodynamic benefit and, over time, a reduction in left ventricular volumes and an increase in left ventricular ejection fraction. CRT can be delivered as a pacing system alone (CRT-P) or in addition to an implantable cardioverter–defibrillator: CRT-D. Advances in device and lead technologies continue to improve successful delivery of CRT, and modern telecommunication technologies enable remote monitoring of device variables and various surrogate markers of heart failure, potentially offering the ability to predict subclinical deterioration and thus allow for timely therapeutic intervention.
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Verma, Atul Kumar, Indu Saini, and Barjinder Singh Saini. "Electrocardiogram Dynamic Interval Feature Extraction for Heartbeat Characterization." In Medical Data Security for Bioengineers, 242–53. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-7952-6.ch012.

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In the chapter, dynamic time domain features are extracted in the proposed approach for the accurate classification of electrocardiogram (ECG) heartbeats. The dynamic time-domain information such as RR, pre-RR, post-RR, ratio of pre-post RR, and ratio of post-pre RR intervals to be extracted from the ECG beats in proposed approach for heartbeat classification. These four extracted features are combined and fed to k-nearest neighbor (k-NN) classifier with tenfold cross-validation to classify the six different heartbeats (i.e., normal [N], right bundle branch block [RBBB], left bundle branch block [LBBB], atrial premature beat [APC], paced beat [PB], and premature ventricular contraction[PVC]). The average sensitivity, specificity, positive predictivity along with overall accuracy is obtained as 99.77%, 99.97%, 99.71%, and 99.85%, respectively, for the proposed classification system. The experimental result tells that proposed classification approach has given better performance as compared with other state-of-the-art feature extraction methods for the heartbeat characterization.
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Maceira, Alicia M., and Alistair A. Young. "Global and regional cardiac function." In The EACVI Textbook of Cardiovascular Magnetic Resonance, edited by Massimo Lombardi, Sven Plein, Steffen Petersen, Chiara Bucciarelli-Ducci, Emanuela R. Valsangiacomo Buechel, Cristina Basso, and Victor Ferrari, 92–102. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198779735.003.0014.

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Cardiovascular magnetic resonance is currently the most accurate and reproducible method for the measurement of biventricular global and regional systolic function, as well as diastolic and atrial function. Regional wall motion can be visually evaluated and quantified with tissue tagging or feature tracking analysis techniques. Wall motion analysis is usually performed at rest but can also be done with low-dose and high-dose dobutamine. Segmental strain is best measured with tissue tagging or displacement-encoded phase contrast imaging. Current analysis software enables the measurement of ventricular volumes throughout the cardiac cycle, and assessment of left and right ventricular diastolic function can be done by evaluating the time–flow curve, derived from the volume–time curve obtained in the volumetric analysis. Although contrast between flowing blood and the myocardium in cardiac cine images is typically excellent, the precise placement of the contours is reader-dependent and training is highly recommended due to the subjective nature of contour placement.
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