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Nakai, Toshiko, Hiroaki Mano, Yukitoshi Ikeya, Yoshihiro Aizawa, Sayaka Kurokawa, Kimie Ohkubo, Koichi Nagashima, Ichiro Watanabe, and Yasuo Okumura. "Narrower QRS may be enough to respond to cardiac resynchronization therapy in lightweight patients." Heart and Vessels 35, no. 6 (November 27, 2019): 835–41. http://dx.doi.org/10.1007/s00380-019-01541-8.
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AbstractA prolonged QRS duration (QRSd) is promising for a response to cardiac resynchronization therapy (CRT). The variation in human body sizes may affect the QRSd. We hypothesized that conduction disturbances may exist in Japanese even with a narrow (< 130 ms)-QRS complex; such patients could be CRT candidates. We investigated the relationships between QRSd and sex and body size in Japanese. We retrospectively analyzed the values of 338 patients without heart failure (HF) (controls) and 199 CRT patients: 12-lead electrocardiographically determined QRSd, left ventricular diastolic and systolic diameters (LVDd and LVDs), body surface area (BSA), body mass index (BMI), and LVEF. We investigated the relationships between the QRSd and BSA, BMI, and LVD. The men’s and women’s BSA values were 1.74 m2 and 1.48 m2 in the controls (p < 0.0001), and 1.70 m2 and 1.41 m2 in the CRT patients (p < 0.0001). The men’s and women’s QRSd values were 96.1 ms and 87.4 ms in the controls (p < 0.0001), and 147.8 ms and 143.9 ms in the CRT group (p = 0.4633). In the controls, all body size and LVD variables were positively associated with QRSd. The CRT response rate did not differ significantly among narrow-, mid-, and wide-QRS groups (83.6%, 91.3%, 92.4%). An analysis of the ROC curve provided a QRS cutoff value of 114 ms for CRT responder. The QRSd appears to depend somewhat on body size in patients without HF. The CRT response rate was better than reported values even in patients with a narrow QRSd (< 130 ms). When patients are considered for CRT, a QRSd > 130 ms may not be necessary, and the current JCS guidelines appear to be appropriate.
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Odland, Hans Henrik, Torbjørn Holm, Lars Ove Gammelsrud, Richard Cornelussen, and Erik Kongsgaard. "Determinants of LV dP/dtmax and QRS duration with different fusion strategies in cardiac resynchronisation therapy." Open Heart 8, no. 1 (May 2021): e001615. http://dx.doi.org/10.1136/openhrt-2021-001615.
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BackgroundWe designed this study to assess the acute effects of different fusion strategies and left ventricular (LV) pre-excitation/post-excitation on LV dP/dtmax and QRS duration (QRSd).MethodsWe measured LV dP/dtmax and QRSd in 19 patients having cardiac resynchronisation therapy (CRT). Two groups of biventricular pacing were compared: pacing the left ventricle (LV) with FUSION with intrinsic right ventricle (RV) activation (FUSION), and pacing the LV and RV with NO FUSION with intrinsic RV activation. In the NO FUSION group, the RV was paced before the expected QRS onset. A quadripolar LV lead enabled distal, proximal and multipoint pacing (MPP). The LV was stimulated relative in time to either RV pace or QRS-onset in four pre-excitation/post-excitation classes (PCs). We analysed the interactions of two groups (FUSION/NO FUSION) with three different electrode configurations, each paced with four different degrees of LV pre-excitation (PC1–4) in a statistical model.ResultsLV dP/dtmax was higher with NO FUSION than with FUSION (769±46 mm Hg/s vs 746±46 mm Hg/s, p<0.01), while there was no difference in QRSd (NO FUSION 156±2 ms and FUSION 155±2 ms). LV dP/dtmax and QRSd increased with LV pre-excitation compared with pacing timed to QRS/RV pace-onset regardless of electrode configuration. Overall, pacing LV close to QRS-onset (FUSION) with MPP shortened QRSd the most, while LV dP/dtmax increased the most with LV pre-excitation.ConclusionWe show how a beneficial change in QRSd dissociates from the haemodynamic change in LV dP/dtmax with different biventricular pacing strategies. In this study, LV pre-excitation was the main determinant of LV dP/dtmax, while QRSd shortens with optimal resynchronisation.
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Karaca, Oguz. "Prognostic Implications of ‘Paced’ and ‘Native’ QRS Durations Following Cardiac Resynchronization Therapy." European Journal of Arrhythmia & Electrophysiology 02, no. 01 (2016): 30. http://dx.doi.org/10.17925/ejae.2016.02.01.30.
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Current evidence strongly suggests that the extent of electrical dyssynchrony within the left ventricle is determined by the delayed intraventricular conduction time reflected by a prolonged QRS duration (QRSd) on the surface (ECG). However, in cardiac resynchronization therapy (CRT) follow-up algorithms, the QRSd on the post-operative ECG has been relatively less frequently addressed, although the baseline QRSd is accepted as an essential ‘pre-operative’ marker for patient selection and prediction of response to therapy. In this review, we discuss the clinical impact of post-implantation electrocardiographic parameters, such as the ‘paced’ QRSd and ‘native’ QRSd (assessed when the device is temporarily switched off) on the efficacy of therapy and on prediction of future outcomes after CRT.
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Kwon, Hee-Jin, Kyoung-Min Park, Seong Soo Lee, Young Jun Park, Young Keun On, June Soo Kim, and Seung-Jung Park. "Electrical Reverse Remodeling of the Native Cardiac Conduction System after Cardiac Resynchronization Therapy." Journal of Clinical Medicine 9, no. 7 (July 8, 2020): 2152. http://dx.doi.org/10.3390/jcm9072152.
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Background: Little is known about electrical remodeling of the native conduction systems, particularly how the PR interval changes, after cardiac resynchronization therapy (CRT). We investigated the effects of CRT on the intrinsic PR interval (i-PRi) and QRS duration (i-QRSd). Methods and results: In 100 consecutive CRT recipients with sinus rhythm and long-term follow-up (>1 year), the i-PRi and i-QRSd were measured at baseline and at the last echocardiographic follow-up (33.4 ± 17.9 months) with biventricular pacing temporarily withdrawn. The relative decrease in the left ventricular end-systolic volume (LVESV) was measured to define CRT-responders (≥15%) and super-responders (≥30%). Following CRT, the left ventricular (LV) ejection fraction increased significantly (p < 0.001). In CRT-responders (n = 71), the LVESV and i-QRSd decreased markedly (170 ± 39 to 159 ± 24 ms, p = 0.012). However, the i-PRi was not shortened with CRT response and was actually likely to increase, even in the super-responder group (n = 33). Moreover, lengthening of the i-PRi was observed consistently irrespective of the CRT response status, beta-blocker use, or amiodarone use. CRT non-responders were associated with a remarkable PR prolongation (p = 0.005) and QRS widening (p = 0.001), along with positive ventricular remodeling. Conclusion: LV volume and i-QRSd decreased markedly with CRT response. However, the i-PRi was not shortened, but rather increased regardless of the degree of CRT response. CRT non-response was associated with a considerable increase in the i-PRi and i-QRSd, along with positive ventricular remodeling. CRT-induced electrical reverse remodeling might occur preferentially in the intraventricular, but not the atrioventricular, conduction system.
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Rehman Mir, Naeem-ur, Naeem Asghar, and Shaukat Javed. "HEART FAILURE;." Professional Medical Journal 24, no. 06 (June 5, 2017): 912–18. http://dx.doi.org/10.29309/tpmj/2017.24.06.1198.
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Introduction: Atrial fibrillation (AF) and wider QRS duration have long beenidentified to worsen heart failure and LV dysfunction and increase cardiovascular morbidityand mortality. Therefore, it is necessary to identify those patients of heart failure who are atgreater risk for cardiovascular morbidity and mortality so that such subjects may be focusedfor preventive strategies. An association exists between QRS duration and AF with greaterincidences of cardiovascular events in patients of heart failure with LV systolic dysfunction.Study Design: Cross sectional survey. Setting: Department of Cardiology, Punjab Institute ofCardiology Lahore. Period: 16-02-2015 to 15-08-2015. Material and Methods: The objectiveof study was to determine the Frequency of QRS Duration groups and Atrial Fibrillation inPatients with Left Ventricular Dysfunction. Sample size of 400 cases was calculated with 95%confidence level, 4% margin of error and taking expected percentage of atrial fibrillation innarrow QRS group i.e. 20.9% (least among all) in patients with left ventricular dysfunction.Sampling technique was non-probability, purposive sampling. Result: The study populationconsisted of male (72.3%) and female (27.7%). Mean LA diameter was 40.3±6.08 mm andmean LV ejection fraction 31.8±6.6 % in the study population. Ischemic heart disease wasthe most common cause of LV dysfunction (88.3%) followed by non-ischemic cardiomyopathy(8.75%) and non-Ischemic valvular heart disease (3.5%). The frequency of Narrow QRSd (<120ms) was 62%, Intermediate QRSd (120-150 ms) was 26.5% and Wide QRSd (>150 ms) was11.5%. The frequency of atrial fibrillation in study population was 15.75%. The frequency of atrialfibrillation was highest in Wide QRSd group (>150 ms) i.e. (60.9%), followed by IntermediateQRSd group (120-150 ms) i.e. (18.9%) and narrow QRSd group (<120 ms) i.e. (6.04%). Patientwith atrial fibrillation were more likely to have poor ejection fraction (P<0.0023) and wider QRSduration (P<0.0001). Frequency of atrial fibrillation was highest in Valvular Cardiomyopathy(non-ischemic valvular heart disease) patients (42.8%) as compared to coronary artery diseasegroup (15.3%) and non-ischemic cardimyopathy group (9.4%). Conclusion: In patients of heartfailure with reduced ejection fraction (HFrEF), the frequency of atrial fibrillation increases asQRS duration widens. This group of patients must be focused for AF preventive strategies.
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Waddingham, Peter H., Pier Lambiase, Amal Muthumala, Edward Rowland, and Anthony WC Chow. "Fusion Pacing with Biventricular, Left Ventricular-only and Multipoint Pacing in Cardiac Resynchronisation Therapy: Latest Evidence and Strategies for Use." Arrhythmia & Electrophysiology Review 10, no. 2 (July 13, 2021): 91–100. http://dx.doi.org/10.15420/aer.2020.49.
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Despite advances in the field of cardiac resynchronisation therapy (CRT), response rates and durability of therapy remain relatively static. Optimising device timing intervals may be the most common modifiable factor influencing CRT efficacy after implantation. This review addresses the concept of fusion pacing as a method for improving patient outcomes with CRT. Fusion pacing describes the delivery of CRT pacing with a programming strategy to preserve intrinsic atrioventricular (AV) conduction and ventricular activation via the right bundle branch. Several methods have been assessed to achieve fusion pacing. QRS complex duration (QRSd) shortening with CRT is associated with improved clinical response. Dynamic algorithm-based optimisation targeting narrowest QRSd in patients with intact AV conduction has shown promise in people with heart failure with left bundle branch block. Individualised dynamic programming achieving fusion may achieve the greatest magnitude of electrical synchrony, measured by QRSd narrowing.
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Uebing, Anselm, Derek G. Gibson, Sonya V. Babu-Narayan, Gerhard P. Diller, Konstantinos Dimopoulos, Omer Goktekin, Mark S. Spence, et al. "Right Ventricular Mechanics and QRS Duration in Patients With Repaired Tetralogy of Fallot." Circulation 116, no. 14 (October 2, 2007): 1532–39. http://dx.doi.org/10.1161/circulationaha.107.688770.
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Background— Patients after repair of tetralogy of Fallot (ToF) frequently have right ventricular (RV) dysfunction and prolonged QRS duration (QRSd) and thus could be candidates for cardiac resynchronization therapy. We aimed to assess the relationship between QRSd and the timing of RV wall motion, including the RV outflow tract (RVOT), in these patients. Methods and Results— Sixty-seven repaired ToF patients (median age, 34 years; interquartile range, 24 to 43 years) and 35 age-matched control subjects were studied by echocardiography and cardiovascular magnetic resonance (n=55 of 67 ToF patients). Time intervals of the RV cardiac cycle were measured from Doppler recordings. Long-axis M-mode recordings were acquired from the right ventricular (RV) free wall and RV outflow tract (RVOT), and the delay in onset of long-axis shortening was measured. ToF patients showed minor abnormalities of the RV cardiac cycle unrelated to QRSd. RV ejection time was prolonged and correspondingly filling time was reduced compared with control subjects (22.3±2.6 versus 20.0±2.9 s/min, P <0.0001; 29.0±3.8 versus 32.7±3.5 s/min, P <0.0001). Total isovolumic time was normal in ToF patients (8.7±4.0 versus 7.4±2.9 s/min; P =NS). QRSd correlated with the delay in RV free wall motion ( r =0.55, P <0.0001) and more so with the delay in RVOT shortening ( r =0.82, P <0.0001). QRSd also correlated with measures of RVOT abnormality such as long-axis RVOT excursion and akinetic area length ( r =−0.46, P =0.004; r =0.33, P =0.01). Conclusions— QRSd in postoperative ToF patients reflects mainly abnormalities of the RVOT rather than the RV body itself. Thus, prevention and treatment of mechanical asynchrony and malignant arrhythmia should focus on the RV infundibulum. Indications for cardiac resynchronization therapy after ToF repair warrant further investigation.
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Tse, Gary, and Bryan P. Yan. "Novel arrhythmic risk markers incorporating QRS dispersion: QRSd × (T peak − T end )/QRS and QRSd × (T peak − T end )/(QT × QRS)." Annals of Noninvasive Electrocardiology 22, no. 6 (August 18, 2016): e12397. http://dx.doi.org/10.1111/anec.12397.
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Carvalho, Elizabeth Regina, Evandro Zacché, Michelli Fenerich, Aparecido Antônio Camacho, Julio P. Santos, and Marlos G. Sousa. "Electrocardiographic markers of myocardial conduction and repolarization in Boxer dogs." Pesquisa Veterinária Brasileira 40, no. 8 (August 2020): 630–36. http://dx.doi.org/10.1590/1678-5150-pvb-6265.
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ABSTRACT: Electrocardiographic markers have been used in people to classify arrhythmogenic risk. The aims of this study were to investigate electrocardiographic markers of conduction and repolarization in Boxers and non-Boxer dogs, and compare such findings between groups. Ten-lead standard electrocardiograms of Boxer dogs and non-Boxers recorded from 2015 to 2018 were retrospectively reviewed. Dogs ≥4 years of age and weighing >20kg were included. Animals with valvular insufficiencies, congenital cardiopathies, cardiac dilation, suspected systolic dysfunction, biphasic T-wave, bundle branch blocks, and those receiving antiarrhythmics were excluded. Electrocardiographic markers of conduction, QRS duration (QRSd) and dispersion (QRSD), and repolarization (corrected QT interval, Tpeak-Tend, JT and JTpeak), as well as derived indices, were measured. Two hundred dogs met the inclusion/exclusion requirements, including 97 Boxers (8.1±2.5 years old; 30±7kg) and 103 non-Boxer (8.8±2.5 years old, 30±8kg). QRSd and QRSD, and repolarization markers in lead II and left precordial lead V4 were considered similar between groups. Dispersion of late repolarization on lead rV2, Tpeak-Tend interval, was considered longer in Boxers (45±8ms vs 38±10ms, P=0.01). The Tpeak-Tend/JTpeak and the JTpeak/JT also differed between groups. Our results indicate that the dispersion of myocardial late repolarization in lead rV2 is slower in Boxers than other dog breeds.
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Harb, Serge C., Saleem Toro, Jennifer A. Bullen, Nancy A. Obuchowski, Bo Xu, Kevin M. Trulock, Niraj Varma, et al. "Scar burden is an independent and incremental predictor of cardiac resynchronisation therapy response." Open Heart 6, no. 2 (July 2019): e001067. http://dx.doi.org/10.1136/openhrt-2019-001067.
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ObjectiveDetermine the prognostic impact of scar quantification (scar %) by cardiac magnetic resonance (CMR) in predicting heart failure admission, death and left ventricular (LV) function improvement following cardiac resynchronisation therapy (CRT), after controlling for the presence of left bundle branch block (LBBB), QRS duration (QRSd) and LV lead tip location and polarity.MethodsConsecutive patients who underwent CMR between 2002 and 2014 followed by CRT were included. The primary endpoint was death or heart failure admission. The secondary endpoint was change in ejection fraction (EF) ≥3 months after CRT. Cox proportional hazards, linear regression models and change in the area under the receiver operating characteristic curve (AUC) were used.ResultsA total of 84 patients were included (63% male, 51% with ischaemic cardiomyopathy). After adjusting for clinical factors, presence of LBBB and QRSd and LV lead tip location and polarity, greater scar % remained associated with a higher risk for clinical events (HR=1.06; 95% CI 1.02 to 1.10; p<0.001) and a smaller improvement in EF (slope: −0.61%; 95% CI −0.93% to 0.29%; p<0.001). When adding scar % to QRSd and LBBB, there was significant improvement in predicting clinical events at 3 years (AUC increased to 0.831 from 0.638; p=0.027) and EF increase ≥10% (AUC 0.869 from 0.662; p=0.007).ConclusionScar quantification by CMR has an incremental value in predicting response to CRT, in terms of heart failure admission, death and EF improvement, independent of the presence of LBBB, QRSd, LV lead tip location and polarity.
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Hamlin, Robert. "Importance, but difficulty, in measurement of QRS duration (QRSd)." Journal of Pharmacological and Toxicological Methods 75 (September 2015): 165. http://dx.doi.org/10.1016/j.vascn.2015.08.027.
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Ono, Maki, Akira Mizukami, and Niraj Varma. "Sex-Specific QRS differences in Japanese heart failure patients with QRSd <120 ms." Journal of Electrocardiology 53 (March 2019): e8. http://dx.doi.org/10.1016/j.jelectrocard.2019.01.031.
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Ono, Maki, Akira Mizukami, and Niraj Varma. "Sex-Specific QRS differences in Japanese heart failure patients with QRSd <120 ms." Journal of Electrocardiology 51, no. 6 (November 2018): 1168–69. http://dx.doi.org/10.1016/j.jelectrocard.2018.10.029.
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Ezekowitz, Justin A., Pierre Théroux, Robert Welsh, Iqbal Bata, John Webb, and Paul W. Armstrong. "Insights into the change in brain natriuretic peptide after ST-elevation myocardial infarction (STEMI): why should it be better than baseline?This paper is one of a selection of papers published in this Special Issue, entitled Young Investigators' Forum." Canadian Journal of Physiology and Pharmacology 85, no. 1 (January 2007): 173–78. http://dx.doi.org/10.1139/y06-102.
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While baseline N-terminal brain natriuretic peptide (NT-proBNP) is useful in the prognosis of acute ST-elevation myocardial infarction (STEMI), it is unclear whether a relationship exists between serial NT-proBNP, reperfusion success, and prognosis. We prospectively defined a NT-proBNP analysis in the WEST (Which Early ST-elevation myocardial infarction Therapy) trial that enrolled 304 acute STEMI patients. NT-proBNP (pg/mL) was measured at baseline prior to treatment (n = 258) and 72 to 96 h (n = 247) and 30 days (n = 221) after treatment (ΔNT-proBNP = 72 h value – the baseline NT-proBNP). Reperfusion success was measured by ST-segment resolution at 180 min, infarct size by peak creatine kinase (CK) during the first 24 h, and QRS score at discharge (QRSd). The primary endpoint was a 30 day clinical composite. The ability of either baseline NT-proBNP or ΔNT-proBNP to predict the primary endpoint was compared using single-variable logistic regression and the c-statistic. Median (interquartile range) NT-proBNP in pg/mL was 87 (39–316) at baseline, 864 (338–1857) at 72 h, and 585 (264–1212) at 30 days. ST resolution was inversely correlated with ΔNT-proBNP (r = –0.23, p = 0.002) and 30 day NT-proBNP (30 day NT-proBNP 1016, 828, and 397 for <30%, 30%–70%, ≥70% STR, respectively, p < 0.001). Infarct size was correlated with ΔNT-proBNP by CK (r = 0.41, p < 0.001) and QRSd (r = 0.31, p < 0.001); the 30 day NT-proBNP relationship was similar for CK (r = 0.48, p < 0.001) and QRSd (p = 0.003). The baseline NT-proBNP was associated with an increased 30-day composite endpoint (Q1, 19%; Q2, 20%; Q3, 15%; Q4, 38%; p = 0.03 for trend) as was ΔNT-proBNP (Q1, 16%; Q2, 18%; Q3, 19%; Q4, 37%; p = 0.009 for trend). The c-statistic for baseline, 72 to 96 h, and ΔNT-proBNP was 0.59, 0.61, and 0.62 for the 30-day composite and 0.64, 0.62, and 0.62 for the 90-day composite, respectively. ΔNT-proBNP clearly predicts short-term adverse cardiac events and is superior to baseline NT-proBNP, but similar to the 72 to 96 h NT-proBNP in predicting clinical events after STEMI. This likely reflects the variability in NT-proBNP at presentation and the ability to integrate subsequent important physiologic sequelae of STEMI such as reperfusion and infarct size.
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Li, Yuqiu, Lirong Yan, Yan Dai, Yu’an Zhou, Qi Sun, Ruohan Chen, Jinxuan Lin, et al. "Feasibility and efficacy of left bundle branch area pacing in patients indicated for cardiac resynchronization therapy." EP Europace 22, Supplement_2 (December 2020): ii54—ii60. http://dx.doi.org/10.1093/europace/euaa271.
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Abstract Aims The present study was to evaluate the feasibility and clinical outcomes of left bundle branch area pacing (LBBAP) in cardiac resynchronization therapy (CRT)-indicated patients. Methods and results LBBAP was performed via transventricular septal approach in 25 patients as a rescue strategy in 5 patients with failed left ventricular (LV) lead placement and as a primary strategy in the remaining 20 patients. Pacing parameters, procedural characteristics, electrocardiographic, and echocardiographic data were assessed at implantation and follow-up. Of 25 enrolled CRT-indicated patients, 14 had left bundle branch block (LBBB, 56.0%), 3 right bundle branch block (RBBB, 12.0%), 4 intraventricular conduction delay (IVCD, 16.0%), and 4 ventricular pacing dependence (16.0%). The QRS duration (QRSd) was significantly shortened by LBBAP (intrinsic 163.6 ± 29.4 ms vs. LBBAP 123.0 ± 10.8 ms, P < 0.001). During the mean follow-up of 9.1 months, New York Heart Association functional class was improved to 1.4 ± 0.6 from baseline 2.6 ± 0.6 (P < 0.001), left ventricular ejection fraction (LVEF) increased to 46.9 ± 10.2% from baseline 35.2 ± 7.0% (P < 0.001), and LV end-diastolic dimensions (LVEDD) decreased to 56.8 ± 9.7 mm from baseline 64.1 ± 9.9 mm (P < 0.001). There was a significant improvement (34.1 ± 7.4% vs. 50.0 ± 12.2%, P < 0.001) in LVEF in patients with LBBB. Conclusion The present study demonstrates the clinical feasibility of LBBAP in CRT-indicated patients. Left bundle branch area pacing generated narrow QRSd and led to reversal remodelling of LV with improvement in cardiac function. LBBAP may be an alternative to CRT in patients with failure of LV lead placement and a first-line option in selected patients such as those with LBBB and heart failure.
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Chamas, P. P. C., V. M. C. Oliveira, F. L. Yamaki, and M. H. M. A. Larsson. "Time-domain signal-averaged electrocardiogram in healthy German Shepherd and Boxer dogs." Arquivo Brasileiro de Medicina Veterinária e Zootecnia 66, no. 3 (June 2014): 778–86. http://dx.doi.org/10.1590/1678-41626148.
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Signal-averaged electrocardiogram (SAECG) identifies ventricular late potentials (LP), low-amplitude electrical signals that are markers of slow cardiac conduction in fibrous myocardium, consisting in a predictive factor for sudden death in dogs at risk of sustained ventricular tachycardia. The aim of this study was to establish reference values of SAECG for German Shepherd and Boxer dogs. SAECG was performed in 19 German Shepherd and 28 Boxer client-owned dogs, and parameters analyzed were QRSd (duration of filtered QRS), LAS<40μV (duration of low-amplitude signals in terminal portion of filtered QRS) and RMS40 (root square of mean voltage over the last 40 milliseconds of filtered QRS), with two different filters (25-250 Hz and 40-250 Hz). Statistical analyses was achieved by T Student test (p<0.05) to identify differences between the two groups and between the values obtained with the two filters. No statistical difference was found in SAECG variables between the two breeds with the two different filters (p>0.05). Achieving normal values of SAECG in German Shepherd and Boxer dogs is important to further research late potentials in animals of these breeds with hereditary ventricular tachycardia or arrhythmogenic cardiomyopathy and identification of individuals at high risk of cardiac-related sudden death.
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Cosgun, Ayhan, and Mustafa Hamidullah Türkkanı. "The Relationships between the Repolarisation and Depolarisation Markers of Sudden Cardiac Death in Smokers." Journal of Research in Clinical Medicine 9, no. 1 (December 10, 2020): 5. http://dx.doi.org/10.34172/jrcm.2021.005.
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Backgroung: The risk of sudden cardiac death (SCD) and atrial fibrillation (AF) increase in smokers. This study aimed to determine the relationships between the repolarization and depolarization predictors of SCD in routine electrocardiography (ECG) in smokers. Methods: Between January and August-2019, ninety-eight healthy patients smoking for more than five years were included in the study group by simple random sampling. The control group consisted of one hundred twenty-two non-smokers. In the study and control group, following a routine physical examination and blood tests, P wave dispersion in the right precordial leads (PWdR) and the left precordial leads (PWdL), T peak-end interval in the right precordial leads (Tp-eR) and the left precordial leads (Tp-eL), QRS dispersion in the right precordial leads (dQRSR) and the left precordial leads (dQRSL), and QRS duration values in the right precordial leads (QRSR) and the left precordial leads (QRSL) were calculated in routine 12-lead ECG + right precordial leads. Results: There was a statistically significant moderate positive correlation between dQRSRxTp-eR/QRSR-value and smoking time in the study group. Also, there was a statistically significant weak negative correlation between dQRSLxTp-eL/QRSL-value and smoking time in the study group (Respectively, R=0.52, and P<0.01, R=0.41 and P<0.01). There was a significant difference between correlation ratio of dQRSRxTp-eR/QRS-value and smoking time and dQRSLxTp-eL/QRSL-value and smoking time in the study group (Z=5.73, p<0.01). Conclusions: In the current smokers, dQRSRxTp-eR/QRSR and dQRSLxTp-eL/QRSL values significantly higher than in the control group.
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Gadaleta, Matteo, and Agostino Giorgio. "A Method for Ventricular Late Potentials Detection Using Time-Frequency Representation and Wavelet Denoising." ISRN Cardiology 2012 (August 26, 2012): 1–9. http://dx.doi.org/10.5402/2012/258769.
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This study proposes a method for ventricular late potentials (VLPs) detection using time-frequency representation and wavelet denoising in high-resolution electrocardiography (HRECG). The analysis is performed both with the signal averaged electrocardiography (SAECG) and in real time. A comparison between the temporal and the time-frequency analysis is also reported. In the first analysis the standard parameters QRSd, LAS40, and RMS40 were used; in the second normalized energy in time-frequency domain was calculated. The algorithm was tested adding artificial VLPs to real ECGs.
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Kim, Sungsu, Choong Hwan Kwak, Jaehoon Jung, Jong Ha Baek, Jung Hwa Jung, Ki-Jong Park, Kyongyoung Kim, Soo Kyoung Kim, Dawon Kang, and Jong Ryeal Hahm. "Changes in Serum Electrolytes, ECG, and Baroreflex Sensitivity during Combined Pituitary Stimulation Test." BioMed Research International 2018 (May 9, 2018): 1–11. http://dx.doi.org/10.1155/2018/8692078.
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The mechanisms by which hypoglycemia increases cardiovascular mortality remain unclear. The aim of the study is to investigate changes in serum electrolytes, norepinephrine concentrations, electrocardiography, and baroreflex sensitivity (BRS) and associations between corrected QT (QTc) intervals and the changes in serum electrolytes during combined pituitary stimulation test (CPST). We recruited the subjects who were admitted to the Gyeongsang National University Hospital to undergo CPST between September 2013 and December 2014. Participants were 12 patients suspected of having hypopituitarism. Among 12 patients, cardiac arrhythmia in two patients occurred during hypoglycemia. There were significant differences in serum levels of potassium (P<0.001), sodium (P=0.003), chloride (P=0.002), and calcium (P=0.017) at baseline, hypoglycemia, and 30 and 120 minutes after hypoglycemia. Also, there was a significant increase in heart rate (P=0.004), corrected QT (QTc) interval (P=0.008), QRS duration (P=0.021), and BRS (P=0.005) at hypoglycemia, compared to other time points during CPST. There was a positive association between QTc intervals and serum sodium levels (P<0.001) in 10 patients who did not develop arrhythmia during CPST. This study showed that there were significant changes in serum levels of potassium, sodium, chloride, and calcium, as well as heart rate, QTc interval, QRSd, and BRS during CPST. It was revealed that QTc intervals had a significant association with concentrations of sodium.
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Ferdaushi, Umme Habiba, M. Atahar Ali, Shaila Nabi, Mainul Islam, Md Shamshul Alam, and Md Arifur Rahman. "Evaluation of Morphology of Premature Ventricular Contraction on 12-Lead Electrocardiogram." Bangladesh Heart Journal 31, no. 2 (April 28, 2017): 74–79. http://dx.doi.org/10.3329/bhj.v31i2.32378.
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Background-Evaluation of different morphology of premature ventricular contraction (PVC) in 12-lead ECG might reflect the presence or absence of myocardial diseases and determine PVC foci. It is important for ablation procedure and it can help in pre-procedural planning and potentially may improve ablation outcome.Methods and Results-In this study, 12-lead Electrocardiogram (ECG) of 50 patients with or without structural cardiac diseases, who had experienced PVC, were obtained. PVC QRS duration, contour, pattern, unifocal or multifocaland different morphology in various lead were evaluated. PVC-QRS morphology of 50 ECGs showed QRSd d 140ms was 60%, >140ms was 24%, >160ms was 16%. QRS notching <40ms was 42%, >40ms was 16%, smooth contour was 42%. The morphology of PVCs in lead V1, RBBB morphology was 36%, LBBB morphology was 64%; in lead V1 & V2, high r 8%, low r 4%. QRS wave polarity in lead I negative (QS, Qr, or rS wave pattern) 28%, positive (R-wave pattern) 52%; in lead II, III, avF, positive 76%. Of these RR or Rr pattern 20%, R pattern 56%. Negative 24%. QRS transition in chest lead, 16% transition occur at V4 V5, 48% at V3-V4, 4% at V2-V3, 36% at V1-V2 level. The pattern of PVCs were bigeminy 24%, trigeminy 6%, couplet 4%, salvos 12%, R on T 2%, VT 6%. Of the 32 PVCs originating from the RVOT, 8 were classified as of free-wall origin, 24 of septal, 14 of left, 26 of right, 4 of proximal, and 2 of distal origin. Of the 6 PVCs originating from the LVOT, 4 were originated from the LVOT close to the left coronary cusp and 2 were originated from the LVOT close to the right coronary cusp. Of the 12 PVCs originated from LV fascicle, 12 of posterior fascicle origin and none from anterior fascicle origin.Conclusion-12-lead ECG is a simple, inexpensive and noninvasive tool to detect PVCs and facilitate their localization. By evaluating morphology of PVC, we can also predict the structural and functional state of heart.Bangladesh Heart Journal 2016; 31(2) : 75-79
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Lei, Juan, Yi Grace Wang, Luna Bhatta, Jamal Ahmed, Dali Fan, Jingfeng Wang, and Kan Liu. "Ventricular geometry–regularized QRSd predicts cardiac resynchronization therapy response: machine learning from crosstalk between electrocardiography and echocardiography." International Journal of Cardiovascular Imaging 35, no. 7 (May 18, 2019): 1221–29. http://dx.doi.org/10.1007/s10554-019-01545-5.
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Pelter, Michele M., Richard Fidler, and Xiao Hu. "Research: Association of Low-Amplitude QRSs with False-Positive Asystole Alarms." Biomedical Instrumentation & Technology 50, no. 5 (September 1, 2016): 329–35. http://dx.doi.org/10.2345/0899-8205-50.5.329.
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Abstract Background: Although electrocardiographic monitoring is valuable for continuous surveillance of intensive care unit (ICU) patients, false alarms are common and have been cited as a cause of alarm fatigue. ANSI/AAMI EC12:2002 states that electrocardiograms (ECGs) should not detect a QRS if the waveform is less than 0.15 mV (1.5 mm) for adult patients, in order to avoid mislabeling P waves or baseline noise as QRSs during complete heart block or asystole. However, ECG software algorithms often use more conservative QRS thresholds, which may result in false-positive asystole alarms in patients with low-amplitude QRS complexes. Objectives: To 1) assess the frequency of low QRS amplitude in a group of ICU patients with one or more false-positive asystole alarms and 2) determine whether low-amplitude QRSs are associated with false-positive asystole alarms during continuous ECG monitoring. Methods: Hospital-acquired standard 12-lead ECGs were examined in a group of 82 ICU patients who had one or more false-positive asystole alarms. Low QRS amplitude was defined as a unidirectional (only positive or negative) QRS of less than 5 mm in two of four leads (I, II, III, and V1). Results: Low-amplitude QRSs were present in 45 of 82 (55%) patients. The presence of low-amplitude QRSs did not differ according to age, sex, or race. Patients treated in the cardiac ICU had the highest proportion of low-amplitude QRSs. An equivalent proportion of patients had false-positive asystole alarms by group (no low-amplitude QRSs 95% vs. low-amplitude QRSs 87%; P = 0.229). Eight patients (10%) had both true- and false-positive asystole alarms (two [5%] with no low-amplitude QRSs and six [13%] with low-amplitude QRSs; P = 0.229). Conclusion: Low-amplitude QRS, as assessed from hospital 12-lead ECGs, occurs frequently and is more common in cardiac ICU patients. However, this ECG feature did not identify patients with false-positive asystole alarms during continuous ECG monitoring.
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Falsaperla, Raffaele, Giovanna Vitaliti, Ausilia Desiree Collotta, Chiara Fiorillo, Alfredo Pulvirenti, Salvatore Alaimo, Catia Romano, and Martino Ruggieri. "Electrocardiographic Evaluation in Patients With Spinal Muscular Atrophy: A Case-Control Study." Journal of Child Neurology 33, no. 7 (April 24, 2018): 487–92. http://dx.doi.org/10.1177/0883073818767170.
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Background: This study aimed to show the impairment of autonomic cardiac conduction causing bradycardia and/or electrocardiographic alterations in children affected by spinal muscular atrophy type 1 and 2 (SMA 1 and 2). Methods: We included 25 spinal muscular atrophy patients, admitted from November 2016 to May 2017. All patients underwent an electrocardiographic examination and we studied PR and QRS intervals, P-waves and QRS amplitudes, and heart rate in spinal muscular atrophy patients compared to a control group. Results: In all patients, we found longer PRi and QRSi ( P < .05), lower P-wave and QRS complex amplitudes ( P < .01), and a decreased heart rate ( P < .01) with respect to controls. When we divided our patients into SMA1 and SMA2 subgroups, we found that statistical differences were maintained for P-wave and QRS complex amplitudes and heart rate, but not for PRi and QRSi with respect to controls. Conclusion: We suggest the hypothesis of SMN expression on cardiac tissue condition and/or autonomic cardiac conduction.
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Desai, Nagaraj, Sunil Kumar S., Guruprasad B. V., and Poornima K. S. "A comparative study to evaluate the clinical utility and performance of a new hand-held mobile electrocardiogram device." International Journal Of Community Medicine And Public Health 7, no. 5 (April 24, 2020): 1726. http://dx.doi.org/10.18203/2394-6040.ijcmph20201971.
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Background: Electrocardiogram (ECG) is a non-invasive test which can provide clue for the presence of cardiac diseases. Simple, handheld devices, sufficiently miniaturized are useful for a widespread use. New devices, however, need to be compared with the standard ones for their performance in the real-world practice. Here in we report clinical utility of a handheld device.Methods: KardioscreenTM is a mobile and handheld device. It’s been approved for safety and performance standards and it has been certified for ‘Conformite Europeenne’ (CE). Using this device, a comparative blinded study with a conventional and commercially available standard 12 lead ECG machine was one. 604 ECGs recorded from 302 patients with various clinical disorders were coded and analyzed by two blinded observers. A third cardiologist adjudicated the reports. The reports were then correlated for the ECG patterns generated and with the clinical diagnosis. Computer generated measurements of various durations and intervals were also analyzed and compared. Regression analysis was used to compare the values. SPSS 21 software was used to analyze the data.Results: Kardioscreen device could provide recordings to diagnose including ST elevation (99%), non-ST elevation myocardial infarction (94.1%), chamber-hypertrophy (87%), conduction blocks (99%), and arrhythmias (96.4%), with good correlations with the comparator for pattern recognition. Also, computer generated measurements were significantly correlated with the comparator (R=0.96 for HR, R=0.82 for QRSd, R=0.86 for QT/QTc, R=0.76 for PR).Conclusions: The Kardioscreen device is a reliable tool for electrocardiographic diagnosis of common clinical cardiac disorders.
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Cohen, Roni, Melissa R. Suzuki, and Kenneth E. Hammel. "Differential Stress-Induced Regulation of Two Quinone Reductases in the Brown Rot Basidiomycete Gloeophyllum trabeum." Applied and Environmental Microbiology 70, no. 1 (January 2004): 324–31. http://dx.doi.org/10.1128/aem.70.1.324-331.2004.
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ABSTRACT Quinone reductases (QRDs) have two important functions in the basidiomycete Gloeophyllum trabeum, which causes brown rot of wood. First, a QRD is required to generate biodegradative hydroxyl radicals via redox cycling between two G. trabeum extracellular metabolites, 2,5-dimethoxyhydroquinone (2,5-DMHQ) and 2,5-dimethoxy-1,4-benzoquinone (2,5-DMBQ). Second, because 2,5-DMBQ is cytotoxic and 2,5-DMHQ is not, a QRD is needed to maintain the intracellular pool of these metabolites in the reduced form. Given their importance in G. trabeum metabolism, QRDs could prove useful targets for new wood preservatives. We have identified two G. trabeum genes, each existing in two closely related, perhaps allelic variants, that encode QRDs in the flavodoxin family. Past work with QRD1 and heterologous expression of QRD2 in this study confirmed that both genes encode NADH-dependent, flavin-containing QRDs. Real-time reverse transcription PCR analyses of liquid- and wood-grown cultures showed that qrd1 expression was maximal during secondary metabolism, coincided with the production of 2,5-DMBQ, and was moderately up-regulated by chemical stressors such as quinones. By contrast, qrd2 expression was maximal during fungal growth when 2,5-DMBQ levels were low, yet was markedly up-regulated by chemical stress or heat shock. The total QRD activity in lysates of G. trabeum mycelium was significantly enhanced by induction beforehand with a cytotoxic quinone. The promoter of qrd2 contains likely antioxidant, xenobiotic, and heat shock elements, absent in qrd1, that probably explain the greater response of qrd2 transcription to stress. We conclude from these results that QRD1 is the enzyme G. trabeum routinely uses to detoxify quinones during incipient wood decay and that it could also drive the biodegradative quinone redox cycle. However, QRD2 assumes a more important role when the mycelium is stressed.
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Pollard, James D., Kazi T. Haq, Katherine J. Lutz, Nichole M. Rogovoy, Kevin A. Paternostro, Elsayed Z. Soliman, Joseph Maher, Joao AC Lima, Solomon Musani, and Larisa G. Tereshchenko. "Sex differences in vectorcardiogram of African-Americans with and without cardiovascular disease: a cross-sectional study in the Jackson Heart Study cohort." BMJ Open 11, no. 1 (January 2021): e042899. http://dx.doi.org/10.1136/bmjopen-2020-042899.
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ObjectivesWe hypothesised that (1) the prevalent cardiovascular disease (CVD) is associated with global electrical heterogeneity (GEH) after adjustment for demographic, anthropometric, socioeconomic and traditional cardiovascular risk factors, (2) there are sex differences in GEH and (3) sex modifies an association of prevalent CVD with GEH.DesignCross-sectional, cohort study.SettingProspective African-American The Jackson Heart Study (JHS) with a nested family cohort in 2000–2004 enrolled residents of the Jackson, Mississippi metropolitan area.ParticipantsParticipants from the JHS with analysable ECGs recorded in 2009–2013 (n=3679; 62±12 y; 36% men; 863 family units). QRS, T and spatial ventricular gradient (SVG) vectors’ magnitude and direction, spatial QRS-T angle and sum absolute QRST integral (SAI QRST) were measured.OutcomePrevalent CVD was defined as the history of (1) coronary heart disease defined as diagnosed/silent myocardial infarction, or (2) revascularisation procedure defined as prior coronary/peripheral arterial revascularisation, or (3) carotid angioplasty/carotid endarterectomy, or (4) stroke.ResultsIn adjusted mixed linear models, women had a smaller spatial QRS-T angle (−12.2 (95% CI −19.4 to -5.1)°; p=0.001) and SAI QRST (−29.8 (−39.3 to −20.3) mV*ms; p<0.0001) than men, but larger SVG azimuth (+16.2(10.5–21.9)°; p<0.0001), with a significant random effect between families (+20.8 (8.2–33.5)°; p=0.001). SAI QRST was larger in women with CVD as compared with CVD-free women or men (+15.1 (3.8–26.4) mV*ms; p=0.009). Men with CVD had a smaller T area (by 5.1 (95% CI 1.2 to 9.0) mV*ms) and T peak magnitude (by 44 (95%CI 16 to 71) µV) than CVD-free men. T vectors pointed more posteriorly in women as compared with men (peak T azimuth + 17.2(8.9–25.6)°; p<0.0001), with larger sex differences in T azimuth in some families by +26.3(7.4–45.3)°; p=0.006.ConclusionsThere are sex differences in the electrical signature of CVD in African-American men and women. There is a significant effect of unmeasured genetic and environmental factors on cardiac repolarisation.
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van Oosterom, Adriaan. "The case of the QRS-T angles versus QRST integral maps." Journal of Electrocardiology 47, no. 2 (March 2014): 144–50. http://dx.doi.org/10.1016/j.jelectrocard.2013.10.006.
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Kozmann, Gyorgy, Robert L. Lux, and Larry S. Green. "Comparison of the diagnostic properties of QRS and QRST isointegral maps." Journal of Electrocardiology 23, no. 3 (July 1990): 278. http://dx.doi.org/10.1016/0022-0736(90)90178-5.
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Wenz, H., H. Dickhaus, and C. Maier. "Robust Detection of Sleep Apnea from Holter ECGs." Methods of Information in Medicine 53, no. 04 (2014): 303–7. http://dx.doi.org/10.3414/me13-02-0043.
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SummaryIntroduction: This article is part of the Focus Theme of Methods of Information in Medicine on “Biosignal Interpretation: Advanced Methods for Studying Cardiovascular and Respiratory Systems”.Objectives: Detect presence of sleep-related breathing disorders (SRBD) in epochs of 1 min by signal analysis of Holter ECG recordings.Methods: In 121 patients, 140 synchronized polysomnograms (PSGs) and 8-channel Holter ECGs were recorded. The only excluded condition was persistent arrhythmias. Respiratory events as scored from the PSGs were mapped to a 1 min grid and served as reference for ECG-based detection. Moreover, 69/70 recordings of the Physionet Sleep Apnea ECG Database (PADB) were included. We performed receiver operating characteristics analysis of a single, novel time-domain feature, the joint local similarity index (jLSI). Based on cross-correlation, the jLSI quantifies the time-locked occurrence of characteristic low-frequency (LF) modulations in ECG respiratory myogram interference (RMI), QRS amplitude (QRSA) and heart rate.Results: Joint oscillations in QRSA, RMI and the envelope of RMI identified positive epochs with a sensitivity of 0.855 (PADB: 0.873) and a specificity of 0.86 (PADB: 0.88). Inclusion of heart rate did not improve detection accuracy.Conclusions: Joint occurrence of LF-modulations in QRSA and RMI is a characteristic feature of SRBD that is robustly quantified by the jLSI and permits reliable and reproducible detection of sleep apnea in very heterogeneous settings.
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Tereshchenko, Larisa G., Alan Cheng, Barry J. Fetics, Joseph E. Marine, David D. Spragg, Sunil Sinha, Hugh Calkins, Gordon F. Tomaselli, and Ronald D. Berger. "Ventricular arrhythmia is predicted by sum absolute QRST integralbut not by QRS width." Journal of Electrocardiology 43, no. 6 (November 2010): 548–52. http://dx.doi.org/10.1016/j.jelectrocard.2010.07.013.
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Oikarinen, L., M. Karvonen, M. Viitasalo, P. Takala, M. Kaartinen, J. Rossinen, I. Tierala, et al. "Electrocardiographic assessment of left ventricular hypertrophy with time–voltage QRS and QRST-wave areas." Journal of Human Hypertension 18, no. 1 (December 17, 2003): 33–40. http://dx.doi.org/10.1038/sj.jhh.1001631.
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Vásquez, Javier Pinos, Tiago Luiz Luz Leiria, Clóvis Froemming Jr, Bruno Schaaf Finkler, Danilo Barros Zanotta, Thiago Camargo Moreira, Marcelo Lapa Kruse, Leonardo Martins Pires, and Gustavo Glotz de Lima. "Early Repolarization, Fragmented QRS and Tpeak-Tend Interval as Electrocardiographic Markers in Patients with Idiopathic Ventricular Arrhythmias: a Brief Review." Journal of Cardiac Arrhythmias 33, no. 3 (November 6, 2020): 142–46. http://dx.doi.org/10.24207/jca.v33i3.3394.
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Introduction: Idiopathic ventricular tachycardia and ventricular fibrillation, as causes of sudden cardiac death, are entities with mechanisms poorly studied and understood to date. The electrocardiogram (ECG) is a simple tool, but with great diagnostic and prognostic value, which has allowed the identification of certain markers associated with increased risk of development of malignant ventricular arrhythmias and sudden cardiac death. Methods: To identify the electrocardiographic markers related to the risk of developing idiopathic malignant ventricular arrhythmias, a review of the literature was performed, looking for the most recent articles with the greatest scientific impact on the topic. Outcome: Although the number of studies published to date is scarce, the published evidence has shown three electrocardiographic risk markers that have emerged in recent years and which have been related to the development of idiopathic malignant ventricular arrhythmias: the early repolarization (ER) pattern, QRS fragmentation (QRSF) and the Tpeak-Tend (Tp-Te) interval. The ECG marker that has shown most evidence to date is the pattern of ER, as a cause of changes in both ventricular depolarization and repolarization. The QRSF and the Tp-Te interval have also been related to the development of idiopathic ventricular arrhythmias, although with less evidence in this regard. Conclusion: In the last years, three electrocardiographic markers have appeared as variables related to the development of malignant ventricular arrhythmias, as is the case of ER, QRSF and Tp-Te interval. However, evidence is scarce in this specific patient profile and further randomized clinical trials are necessary to demonstrate its true relationship and usefulness.
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Karvounis, E. C., M. G. Tsipouras, C. Papaloukas, D. G. Tsalikakis, K. K. Naka, and D. I. Fotiadis. "A Non-invasive Methodology for Fetal Monitoring during Pregnancy." Methods of Information in Medicine 49, no. 03 (2010): 238–53. http://dx.doi.org/10.3414/me09-01-0041.
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Summary Objectives: This paper describes a methodology for the monitoring of the fetal cardiac health status during pregnancy, through the effective and non-invasive monitoring of the abdominal ECG signals (abdECG) of the mother. Methods: For this purpose, a three-stage methodology has been developed. In the first stage, the fetal heart rate (fHR) is extracted from the abdECG signals, using nonlinear analysis. Also, the eliminated ECG (eECG) is calculated, which is the abdECG after the maternal QRSs elimination. In the second stage, a blind source separation technique is applied to the eECG signals and the fetal ECG (fECG) is obtained. Finally, monitoring of the fetus is implemented using features extracted from the fHR and f ECG, such as the T/QRS ratio and the characterization of the fetal ST waveforms. Results: The methodology is evaluated using a dataset of simulated multichannel abdECG signals: 94.79% accuracy for fHR extraction, 92.49% accuracy in T/QRS ratio calculation and 79.87% in ST waveform classification. Conclusions: The novel non-invasive proposed methodology is advantageous since it offers automated identification of fHR and fECG and automated ST waveform analysis, exhibiting a high diagnostic accuracy.
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Shoji, Yasushi, Ryo Tamaki, and Yoshitaka Okada. "Temperature Dependence of Carrier Extraction Processes in GaSb/AlGaAs Quantum Nanostructure Intermediate-Band Solar Cells." Nanomaterials 11, no. 2 (January 29, 2021): 344. http://dx.doi.org/10.3390/nano11020344.
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From the viewpoint of band engineering, the use of GaSb quantum nanostructures is expected to lead to highly efficient intermediate-band solar cells (IBSCs). In IBSCs, current generation via two-step optical excitations through the intermediate band is the key to the operating principle. This mechanism requires the formation of a strong quantum confinement structure. Therefore, we focused on the material system with GaSb quantum nanostructures embedded in AlGaAs layers. However, studies involving crystal growth of GaSb quantum nanostructures on AlGaAs layers have rarely been reported. In our work, we fabricated GaSb quantum dots (QDs) and quantum rings (QRs) on AlGaAs layers via molecular-beam epitaxy. Using the Stranski–Krastanov growth mode, we demonstrated that lens-shaped GaSb QDs can be fabricated on AlGaAs layers. In addition, atomic force microscopy measurements revealed that GaSb QDs could be changed to QRs under irradiation with an As molecular beam even when they were deposited onto AlGaAs layers. We also investigated the suitability of GaSb/AlGaAs QDSCs and QRSCs for use in IBSCs by evaluating the temperature characteristics of their external quantum efficiency. For the GaSb/AlGaAs material system, the QDSC was found to have slightly better two-step optical excitation temperature characteristics than the QRSC.
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Johnson, John A., Kazi T. Haq, Katherine J. Lutz, Kyle K. Peters, Kevin A. Paternostro, Natalie E. Craig, Nathan W. L. Stencel, Lila F. Hawkinson, Maedeh Khayyat-Kholghi, and Larisa G. Tereshchenko. "Electrophysiological ventricular substrate of stroke: a prospective cohort study in the Atherosclerosis Risk in Communities (ARIC) study." BMJ Open 11, no. 9 (September 2021): e048542. http://dx.doi.org/10.1136/bmjopen-2020-048542.
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ObjectivesThe goal of the study was to determine an association of cardiac ventricular substrate with thrombotic stroke (TS), cardioembolic stroke (ES) and intracerebral haemorrhage (ICH).DesignProspective cohort study.SettingThe Atherosclerosis Risk in Communities (ARIC) study in 1987–1989 enrolled adults (45–64 years), selected as a probability sample from four US communities (Minneapolis, Minnesota; Washington, Maryland; Forsyth, North Carolina; Jackson, Mississippi). Visit 2 was in 1990–1992, visit 3 in 1993–1995, visit 4 in 1996–1998 and visit 5 in 2011–2013.ParticipantsARIC participants with analysable ECGs and no history of stroke were included (n=14 479; age 54±6 y; 55% female; 24% black). Ventricular substrate was characterised by cardiac memory, spatial QRS-T angle (QRS-Ta), sum absolute QRST integral (SAIQRST), spatial ventricular gradient magnitude (SVGmag), premature ventricular contractions (PVCs) and tachycardia-dependent intermittent bundle branch block (TD-IBBB) on 12-lead ECG at visits 1–5.OutcomeAdjudicated TS included a first definite or probable thrombotic cerebral infarction, ES—a first definite or probable non-carotid cardioembolic brain infarction. Definite ICH was included if it was the only stroke event.ResultsOver a median 24.5 years follow-up, there were 899 TS, 400 ES and 120 ICH events. Cox proportional hazard risk models were adjusted for demographics, cardiovascular disease, risk factors, atrial fibrillation, atrial substrate and left ventricular hypertrophy. After adjustment, PVCs (HR 1.72; 95% CI 1.02 to 2.92), QRS-Ta (HR 1.15; 95% CI 1.03 to 1.28), SAIQRST (HR 1.20; 95% CI 1.07 to 1.34) and time-updated SVGmag (HR 1.19; 95% CI 1.08 to 1.32) associated with ES. Similarly, PVCs (HR 1.53; 95% CI 1.03 to 2.26), QRS-Ta (HR 1.08; 95% CI 1.01 to 1.16), SAIQRST (HR 1.07; 95% CI 1.01 to 1.14) and time-updated SVGmag (HR 1.11; 95% CI 1.04 to 1.19) associated with TS. TD-IBBB (HR 3.28; 95% CI 1.03 to 10.46) and time-updated SVGmag (HR 1.23; 95% CI 1.03 to 1.47) were associated with ICH.ConclusionsPVC burden (reflected by cardiac memory) is associated with ischaemic stroke. Transient cardiac memory (likely through TD-IBBB) precedes ICH.
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Сахнова, Т. А., Е. В. Блинова, Г. В. Рябыкина, А. А. Белевская, Е. С. Юрасова, О. В. Родненков, Т. В. Мартынюк, and М. А. Саидова. "Type of QRS complex as an indicator of the severity of heart damage in patients with pulmonary hypertension." Kardiologicheskii vestnik, no. 2() (June 9, 2020): 37–45. http://dx.doi.org/10.36396/ms.2020.82.98.006.
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Резюме Изменения электрокардиограммы, в частности, конфигурация комплекса QRS типа qR в отведении V1, являются фактором риска летального исхода у больных легочной артериальной гипертензией. Цель исследования. Сопоставить конфигурацию комплекса QRS в отведении V1 с выраженностью поражения сердца по данным эхокардиографии (ЭхоКГ) у больных идиопатической легочной гипертензией (ИЛГ) и хронической тромбоэмболической легочной гипертензией (ХТЭЛГ). Материалы и методы. У 40 больных ИЛГ и 40 больных ХТЭЛГ в возрасте 45±12 лет при ЭхоКГ оценивали систолическое давление в легочной артерии (СДЛА), размеры камер сердца, показатели систолической и диастолической функции правого желудочка (ПЖ), систолической функции левого желудочка, сердечно-сосудистое сопряжение ПЖ. Конфигурацию комплекса QRS в отведении V1 определяли на 10-ти секундной цифровой электрокардиограмме. Результаты. Было выявлено 18 вариантов конфигурации QRS в отведении V1. У 30 больных (37,5% случаев) в отведении V1 имелась конфигурация rS ил RS; у 16 пациентов (20% случаев) - различные варианты конфигурации rsR’; у 21 пациентов (26% случаев) - конфигурация qR. У пациентов конфигурацией qR в отведении V1 по сравнению с остальными группами были больше СДЛА и размеры правых камер сердца, отмечалось более выраженное ухудшение систолической функции правого и левого желудочков, а также более тяжелые нарушения межжелудочкового взаимодействия и сердечно-сосудистого сопряжения. Конфигурация qR в отведении V1 позволяла с чувствительностью от 46% до 89% и специфичностью от 89% до 95% выявлять больных с наличием прогностически неблагоприятных изменений ЭхоКГ: наличием перикардиального выпота, площадью правого предсердия больше 26 см2, TAPSE меньше 1,5 см. Заключение. Конфигурация комплекса QRS в отведении V1 у больных ИЛГ и ХТЭЛГ отличается большим полиморфизмом. Наиболее тяжелое поражение сердца наблюдается у пациентов с «qR-типом» комплекса QRSв отведении V1. Summary Changes in the electrocardiogram, in particular, the qR pattern in lead V1, are a risk factor for death in patients with pulmonary arterial hypertension. The aim of the work was to compare the QRS pattern in lead V1 with the severity of heart damage according to echocardiography (EchoCG) in patients with idiopathic pulmonary hypertension (IPH) and chronic thromboembolic pulmonary hypertension (CTEPH). Methods. In 40 patients with IPH and 40 patients with CTEPH aged 45 ± 12 years systolic pulmonary artery pressure (SPAP), sizes of heart chambers, systolic and diastolic function of the right ventricle (RV), systolic function of the left ventricle, RV ventricular-arterial coupling were evaluated with EchoCG. The QRS pattern in lead V1 was determined on a 10second digital electrocardiogram. Results. 18 QRS patterns in lead V1 were identified. In 30 patients (37.5% of cases) in lead V1, there was an rS or RS pattern; 16 patients (20% of cases) had different patterns of rsR ’ type; 21 patients (26% of cases) had a qR pattern. Patients with a qR pattern in lead V1 compared with other groups had greater SPAP and sizes of the right chambers of the heart, a more pronounced worsening of systolic function of the right and left ventricles, as well as more severe disturbances of interventricular interaction and ventricular-arterial coupling. The qR pattern in lead V1 made it possible with sensitivity from 46% to 89% and specificity from 89% to 95% to identify patients with prognostically unfavorable changes in EchoCG: presence of pericardial effusion, area of the right atrium more than 26 cm2, TAPSE less than 1.5 cm. Conclusions. The QRS pattern in lead V1 in patients with IPH and CTEPH is characterized by a large polymorphism. The most severe heart damage is observed in patients with the qR pattern in lead V1.
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Buzea, C. A., G. A. Dan, Anca Rodica Dan, Caterina Delcea, M. I. Balea, Daniela Stefana Gologanu, Mihaela Dobranici, and Raluca Alexandra Popescu. "Role of signal-averaged electrocardiography and ventricular late potentials in patients with chronic obstructive pulmonary disease." Romanian Journal Of Internal Medicine 53, no. 2 (June 1, 2015): 133–39. http://dx.doi.org/10.1515/rjim-2015-0018.
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Abstract Patients with chronic obstructive pulmonary disease (COPD) have an increased risk for cardiac arrhythmias. Ventricular late potentials (VLP) on signal-averaged electrocardiography (SAECG) are associated with an increased risk for malignant ventricular arrhythmias. Our aim is to investigate the modifications of SAECG parameters and the presence of VLP as possible indicators of proarrhythmic substrate in patients with COPD. We prospectively enrolled 41 consecutive patients in the COPD group and 63 patients without any history of pulmonary disease, matched for age and hypertension history, in the control group. Pulmonary function tests, arterial blood gases, echocardiography, 24-hour Holter monitoring and SAECG were performed. We measured total filtered QRS duration (QRSf), duration of high frequency, low-amplitude signals < 40 V (HFLA40), and root mean square voltage in the last 40 ms (RMS40). VLP were considered if at least two of these parameters were abnormal. Results. We did not register any significant differences in QRSf, HFLA40 or RMS40 between the two groups. In the COPD group there was a non-significant higher percentage of patients with VLP in comparison with the control group. In the COPD patients we registered a significantly higher number of isolated premature ventricular beats and of combined complex ventricular arrhythmias, consisting of polymorphic PVC, couplets, triplets or nonsustained ventricular tachycardias. None of these arrhythmic parameters correlated with SAECG variables or with the presence of VLP. Conclusion. In COPD patients parameters measured on signal-averaged electrocardiography and ventricular late potentials analysis have little value in risk stratification for ventricular arrhythmias.
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Olshansky, Brian. "Wide QRS, Narrow QRS." Journal of the American College of Cardiology 46, no. 2 (July 2005): 317–19. http://dx.doi.org/10.1016/j.jacc.2005.04.021.
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Poole, Jeanne E., Jagmeet P. Singh, and Ulrika Birgersdotter-Green. "QRS Duration or QRS Morphology." Journal of the American College of Cardiology 67, no. 9 (March 2016): 1104–17. http://dx.doi.org/10.1016/j.jacc.2015.12.039.
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Yu, G. T., J. D. Franckowiak, S. H. Lee, R. D. Horsley, and S. M. Neate. "A novel QTL for Septoria speckled leaf blotch resistance in barley (Hordeum vulgare L.) accession PI 643302 by whole-genome QTL mapping." Genome 53, no. 8 (August 2010): 630–36. http://dx.doi.org/10.1139/g10-032.
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Septoria speckled leaf blotch (SSLB), caused by Septoria passerinii , is one of the most important foliar diseases of barley ( Hordeum vulgare L.) in North America. The primary problem caused by this disease is substantial yield loss. The objective of this study was to determine the chromosomal location of SSLB resistance genes in the barley accession PI 643302. A recombinant inbred line population was developed from the cross Zhenongda 7/PI 643302. PI 643302 is resistant while Zhenongda 7 is susceptible to SSLB. The population was phenotyped for SSLB resistance in five experiments in the greenhouse. A linkage map comprising 113 molecular markers was constructed and simplified composite interval mapping was performed. Two QTLs, designated QrSp-1H and QrSP-2H, were found. QrSp-1H was found on the short arm of chromosome 1H (1HS) in all five experiments and showed a large effect against SSLB. Based on the location of QrSp-1H, it is likely the SSLB resistance gene Rsp2. The QTL QrSp-2H mapped to the distal region on the long arm of chromosome 2H (2HL), had a smaller effect than QrSp-1H, and was also detected consistently in all five experiments. A QTL for SSLB resistance in the same region on chromosome 2H has not been reported previously in either cultivated or wild barley; thus, QrSp-2H is a new QTL for SSLB resistance in barley.
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Glancy, David Luke. "Narrow-QRS and Wide-QRS Tachycardias." American Journal of Cardiology 118, no. 1 (July 2016): 146–48. http://dx.doi.org/10.1016/j.amjcard.2016.04.022.
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Jaroszyński, Andrzej, Anna Jaroszyńska, Anna Szcześniak, Agnieszka Szymczyk, Tomasz Zaborowski, Tomasz Zapolski, Andrzej Wysokiński, and Wojciech Załuska. "Agreement between manual and automated measurements of simple QRS/T angle." Open Medicine 9, no. 6 (December 1, 2014): 737–40. http://dx.doi.org/10.2478/s11536-013-0342-7.
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AbstractThe spatial QRS/T angle (QRS/T) has been identified as a strong and independent predictor of adverse cardiac events. QRS/T can be determined from the electrocardiogram (ECG) by matrix transformation methods or formula which uses a combination of net QRS and T-wave amplitudes (QRS/Tsimple). Amplitudes can be measured automatically by using dedicated software (QRS/Tauto) or can be manually measured on a computer screen (QRS/Tmanual). This latter method allows analysis of QRS/T, when digital ECGs are not available. The aim of the study was to determine the agreement in the measurements between automatically derived QRS and T amplitudes and manually measured on the computer screen amplitudes. The relative error of the QRS/T between the two methods was estimated in 73 patients. In the case of QRS/Tmanual the inter-observer as well as intra-observer variability was estimated. The relative error between QRS/Tauto vs. QRS/Tmanual was 3.51%. Inter-observer and intra-observer variability of the QRS/Tmanual was 1.19% and 1.18% respectively. Manual measurement of the QRS/T is reliable, however, the predictive value of this parameter should be tested in clinical trials, before QRS/Tmanual can be considered a useful tool in clinical practice or retrospective studies.
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Ilhami, Yose Ramda. "PERANAN DURASI QRS DAN SKOR QRS SELVESTER DALAM KEBERHASILAN REPERFUSI MIOKARD." Majalah Kedokteran Andalas 38, no. 4 (April 4, 2016): 218. http://dx.doi.org/10.22338/mka.v38.i4.p218-227.2015.
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AbstrakPerubahan gambaran elektrokardiogram (EKG) terjadi pada fase akut IMA EST baik berupa perubahan repolarisasi ataupun perubahan depolarisasi. Skor QRS Selvester dan pemanjangan kompleks QRS merupakan parameter yang digunakan untuk memperkirakan luas infark dan penilaian iskemia. Tujuan penulisan ini adalah untuk mengetahui mekanisme perubahan durasi QRS dan skor QRS Selvester setelah reperfusi yang optimal. Penulisan artikel ini berdasarkan studi kepustakaan yang terkait dengan peranan durasi QRS dan skor QRS Selvester serta keberhasilan reperfusi miokard. Iskemia mengakibatkan perubahan gambaran listrik sel miokard normal, sehingga terjadi perubahan gambaran EKG yaitu meliputi perubahan gelombang T, elevasi segmen ST dan distorsi dengan pemanjangan kompleks QRS. Penilaian luas infark dapat dilakukan dengan menilai skor QRS Selvester. Iskemia juga mengakibatkan pemanjangan kompleks QRS melalui pemanjangan konduksi purkinye dan blok peri-infark. Reperfusi optimal dapat mengakibatkan regresi gelombang Q dan penurunan durasi kompleks QRS. Perubahan skor QRS selama reperfusi masih kontroversial. Perubahan pada durasi QRS dan skor QRS Selvester sebelum dan setelah reperfusi menandakan bahwa parameter ini merupakan parameter dinamis yang akan berubah ketika terjadinya reperfusi yang optimal pada tingkat seluler.AbstractChanges in Electro Cardiogram (ECG) occur in acute phase of STEMI either as repolarization or depolarization change. Selvester QRS score and lengthening of QRS complex duration are parameters that is used to predict infarct size and to analyze ischemia. The purpose of this literature review is to understand the mechanism of change in QRS duration and Selvester QRS score after optimal reperfusion. Ischemia causes changes in the electrical feature of normal myocardial cells including changes in the T wave, ST segment elevation and distortion with prolongation QRS complex. Assessment of infarct size can be done by assessing Selvester QRS score. Ischemia also resulted in prolongation of the QRS complex with elongation of Purkinje conduction and peri-infarction block. Optimal reperfusion may lead to regression of the Q wave and a decrease in the duration of the QRS complex. QRS score changes during reperfusion remains controversial. Changes in QRS duration and Selvester QRS score before and after reperfusion indicates that these parameters are dynamic parameters that will change when the optimal reperfusion occurs at the cellular level.
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Wilde, A. A. M., and J. S. S. G. de Jong. "Narrow QRS complexes intervening wide QRS complexes." Netherlands Heart Journal 20, no. 12 (November 20, 2012): 518. http://dx.doi.org/10.1007/s12471-012-0337-z.
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Shaik, Zakir, Amanulla Khaji, Scott Goldman, Roberto Rodriguez, Francis P. Sutter, Hafiz M. Waqas Khan, Ahmed Alfityani, et al. "Abstract 308: Aortic Valve Stenosis Causes Both Delayed Ventricular Depolarization and Repolarization." Arteriosclerosis, Thrombosis, and Vascular Biology 36, suppl_1 (May 2016). http://dx.doi.org/10.1161/atvb.36.suppl_1.308.
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Background: Increased QRS duration (QRSD), a common ECG finding in patients (pts) with aortic valve stenosis (AVS), can result in false QT prolongation. This study aimed to test a hypothesis that in AVS delayed ventricular repolarization is independent from the delayed depolarization. Methods: In a retrospective AVS study, ECGs prior to valve repair/replacements were evaluated. QRSD and QTc (Bazett's) were compared between pts with severe and non severe AVS. ECGs showing QRSD > 120 ms or non-sinus rhythm were excluded for analysis. In pts with both wider QRS and longer QT interval (QTc > 440 ms), JT (QT-QRSD) was used to determine the repolarization time. Results: Pts with severe AVS (n=219) had longer QRSD [100 (16) ms vs. 88 (12) ms, p<0.001], with QTc ≥ 450 ms seen in 53%. JT is much longer in the ALQTS group (Table 1). More pts had QTc ≥ 470 ms (33% vs 23%, p<0.05) in the severe AVS than the non-severe AVS. Conclusion: A wider QRS and higher prevalence of moderate to markedly prolonged QT interval in pts with severe AVS indicates AVS itself can result in a delay of both ventricular depolarization and repolarization.
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Jimenez-Candil, Javier, Jose Moriñigo, Maria Ruiz Olgado, Claudio Ledesma, and Cándido Martín-Luengo. "Abstract 2137: Relationship between Duration of Basal QRS Complex and Effectiveness of Antitachycardia Pacing in Implantable Cardioverter-Defibrillator Patients." Circulation 118, suppl_18 (October 28, 2008). http://dx.doi.org/10.1161/circ.118.suppl_18.s_673-b.
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In re-entrant Monomorphic Ventricular Tachycardias (MVT), the ability of Antitachycardia Pacing (APT) to terminate the arrhythmia depends on the presence of an excitable gap (EG) and on the capability of the impulses to penetrate this EG. The main limiting factor for penetrating the EG is the distance and the obstacles between pacing site and circuit. Therefore, the duration of basal QRS complex (QRSd), as marker of left ventricle size, fibrosis and/or necrosis, could be related to the efficacy of ATP. Our aim is to determine the relationship between QRSd and the effectiveness of ATP in terminating MVT. In this prospective study we included 200 ICD patients with substrate for presenting MVT (LVEF: 31±11; pacing site: right ventricular apex). Detection and ATP therapies for MVT were programmed as follows: a) Fast-MVT : Cycle Length (CL): 250 –320 ms; 1 burst of 5 pulses at 84 % of CL, and: b) Slow MVT: CL > 320 ms; 3 bursts of 15 pulses at 91%. QRSd was determined on the surface ECG (50 mm/s) inmediatly before the device implant. During a follow-up of 602±368 days, 546 MVT (CL: 329±35 ms; fast MVT: 41 %; QRSd: 111±25 ms) were recorded in 64 patients. Overall success rate of APT was: 87%. MVT terminated with ATP were associated with QRSd values significantly lower: 109±24 vs. 121±29 (p<0.001). After classifying the events into 3 groups according to the QRSd tertiles (≤100, 101–119, ≥120 ms), the frequency of successful ATP (S-ATP) was higher in the first tertile: 96% vs. 80% (Odds Ratio: 5.8; 95% Confidence Interval: 2.9- 11.6; p<0.001). In a multivariate analysis which included LVEF, aetiology, indication, functional class, CL of MVT, beta-blocker therapy (mgs/day) and left ventricle end-diastolic diameter, QRSd (ms) remained as an independent predictor of S-ATP: Odds Ratio: 0.96 (95% Confidence Interval: 0.94 – 0.97; p<0.001). Patients with lower values of QRSd presented higher rates of S-ATP (mean±standard deviation): 98±4 (QRSd≤100) vs. 81±26 (QRSd: 101–120) vs. 72±40 (QRSd>120); p=0.01 (ANOVA). Among ICD patients, the duration of QRS complex is related to the effectiveness of ATP: for each ms of QRSd the adjusted probability of ATP terminating the episode decreases 4 points. Patients with QRSd≤100 ms have significantly higher rates of S-ATP.
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Chyou, Janice Y., Wan Ting Tay, Inder S. Anand, Tiew‐Hwa Katherine Teng, Jonathan J. L. Yap, Michael R. MacDonald, Vijay Chopra, et al. "Electroanatomic Ratios and Mortality in Patients With Heart Failure: Insights from the ASIAN‐HF Registry." Journal of the American Heart Association 10, no. 6 (March 16, 2021). http://dx.doi.org/10.1161/jaha.120.017932.
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Background QRS duration (QRSd) is a marker of electrical remodeling in heart failure. Anthropometrics and left ventricular size may influence QRSd and, in turn, may influence the association between QRSd and heart failure outcomes. Methods and Results Using the prospective, multicenter, multinational ASIAN‐HF (Asian Sudden Cardiac Death in Heart Failure) registry, this study evaluated whether electroanatomic ratios (QRSd indexed for height or left ventricular end‐diastole volume) are associated with 1‐year mortality in individuals with heart failure with reduced ejection fraction. The study included 4899 individuals (aged 60±19 years, 78% male, mean left ventricular ejection fraction: 27.3±7.1%). In the overall cohort, QRSd was not associated with all‐cause mortality (hazard ratio [HR], 1.003; 95% CI, 0.999–1.006, P =0.142) or sudden cardiac death (HR, 1.006; 95% CI, 1.000–1.013, P =0.059). QRS/height was associated with all‐cause mortality (HR, 1.165; 95% CI, 1.046–1.296, P =0.005 with interaction by sex p interaction =0.020) and sudden cardiac death (HR, 1.270; 95% CI, 1.021–1.580, P =0.032). QRS/left ventricular end‐diastole volume was associated with all‐cause mortality (HR, 1.22; 95% CI, 1.05–1.43, P =0.011) and sudden cardiac death (HR, 1.461; 95% CI, 1.090–1.957, P =0.011) in patients with nonischemic cardiomyopathy but not in patients with ischemic cardiomyopathy (all‐cause mortality: HR, 0.94; 95% CI, 0.79–1.11, P =0.467; sudden cardiac death: HR, 0.734; 95% CI, 0.477–1.132, P =0.162). Conclusions Electroanatomic ratios of QRSd indexed for body size or left ventricular size are associated with mortality in individuals with heart failure with reduced ejection fraction. In particular, increased QRS/height may be a marker of high risk in individuals with heart failure with reduced ejection fraction, and QRS/left ventricular end‐diastole volume may further risk stratify individuals with nonischemic heart failure with reduced ejection fraction. Registration URL: https://Clinicaltrials.gov . Unique identifier: NCT01633398.
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Kaseer, Belal, Bassman Tappuni, Ali AlKhayru, Awfa Zain Elabidin, Vahid Namdarizandi, Gitanjali Lobo, Sai Hanumanthu, et al. "Abstract 12957: Delay in Qrs Interval Predicts Risk of Heart Failure and In-hospital Mortality in Patients Admitted With Atrial Fibrillation With Rapid Ventricular Response." Circulation 142, Suppl_3 (November 17, 2020). http://dx.doi.org/10.1161/circ.142.suppl_3.12957.
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Introduction: Atrial fibrillation is associated with increased risk of heart failure and mortality. The association of QRS duration (QRSd) with morbidity and mortality is understudied in patient with atrial fibrillation (AF) Hypothesis: We sought to investigate the association of prolonged QRSd (≥120 ms) and risk of heart failure and in-hospital death in patients admitted for AF with rapid ventricular response (RVR) Methods: A retrospective study in a community hospital using EPIC database analyzed 1637 patients from 2013-2018 with admission codes of AF with RVR. The cohort was then stratified based on QRSd ≥120ms vs <120ms. A p-value of <0.05 was considered significant Results: Among the 1637 patients who were admitted with AF with RVR, 233 (14%) had QRS ≥120ms. Patient’s characteristics with QRSd≥120 compared to those with QRSd<120ms were mean age [75.9 (11.8) vs 70.9 (13.6), (P<.0001)], history of CAD [41% vs 28%, odds ratio (OR)= 1.78, 95% confidence interval (CI): 1.3-2.3 (P<.0001)], history of PVD [15% vs 7%, OR=2.38, 95% CI: 1.58-3.59 (P<.0001)], history of acute MI [50% vs 33%, OR=1.99, 95% CI:1.5-2.6 (P<.0001)] and CHA2DS2Vasc score [median (IQR) 5(3, 6) vs 4(3, 5) (P<0.001). QRSd≥120ms was associated with higher BNP value [median (IQR) 537(305, 862) vs 371(186, 655) (P<0.001)] and an increased risk of heart failure [(70% vs 55%, OR=1.93, 95% CI:1.43-2.6 (P<.0001)]. Additionally, higher in-hospital mortality rate was observed in patients with QRSd≥120ms [4.3% vs 1.3%, OR=3.11, 95% CI:1.44-6.75 (P=0.006)] Conclusions: In patients who were admitted with AF with RVR, QRSd≥120ms was associated with a higher burden of cardiovascular disease, CHA2DS2Vasc score and an increased risk of heart failure resulting in worse clinical outcomes. Higher median BNP values suggest that worsening heart failure contributed to higher in-hospital mortality. Heart failure associated mortality could be alleviated with medical management or cardiac resynchronization therapy.
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Inoue, Yuko, Hiroshi Ashikaga, Yoshiaki Ohyama, Gustavo Volpe, Bharath Ambale-Venkatesh, and João Lima. "Abstract P094: Gender Difference of Left Ventricular Geometry and Prolonged QRS Duration on Electrocardiogram: MESA (Multi-Ethnic Study of Atherosclerosis)." Circulation 131, suppl_1 (March 10, 2015). http://dx.doi.org/10.1161/circ.131.suppl_1.p094.
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Backgrounds: Prolonged QRS duration (QRSd) on electrocardiogram (ECG) is commonly found in otherwise healthy individuals. However, geometrical factors of the ventricles that determine QRSd are poorly defined. T1 time by cardiovascular magnetic resonance (CMR) is good parameter to estimate extracellular expansion (ECE). Our objective was to evaluate the relationship between QRSd and CMR measures of tissue composition in a large community-based multiethnic population. Methods: A total of 1,615 participants (52% women; age range 44 to 84 years) of the MESA cohort were evaluated with T1 mapping by using 1.5-T CMR scanners. We excluded the participants with focal scar on delayed enhancement CMR and bundle branch block. Midventricular short-axis T1 maps were acquired before and at 12- and 25-min after administration of gadolinium contrast using Modified Look-Locker Inversion Recovery sequence. Results: Longer QRSd was associated with greater LV end diastolic volume (LVEDV) index (p <0.001), LV mass index (p <0.001), and stroke volume index (p <0.01) in both women and men. In addition, longer QRSd was associated with lower ejection fraction (p<0.001), circumferential shortening (p = 0.04), torsion (p <0.001), and longer post-contrast T1 times at 12 min indicating less ECE (p = 0.001) in women only. Longer T1 time remained significant after adjusting for LVEDV, LV mass and QRS voltage. Conclusions: In a large multiethnic population, longer QRSd was associated with lower ECE and LV dysfunction in women. However, these relationships were sex dependent and were absent in men.
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Jain, Rahul, Darshan Dalal, Ariana Evenson, Rohit Jain, Amy Daly, Crystal Tichnell, Cynthia James, Stephen Plantholt, and Hugh Calkins. "Abstract 4116: Electrocardiographic Markers of Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy: A reappraisal." Circulation 118, suppl_18 (October 28, 2008). http://dx.doi.org/10.1161/circ.118.suppl_18.s_832-b.
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Background: The Task Force criteria for diagnosis of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) rely on depolarization and repolarization abnormalities detected on a surface ECG. Terminal activation delay (TAD) has recently been presented as specific and sensitive marker of ARVD/C. The purpose of this study was to evaluate the sensitivity and specificity of TAD in patients with ARVD/C. Methods : In a cohort of 74 patients with definite ARVD/C (51% male); age 36 ± 12 years) and 48 phenotypically normal non cardiac patients (35% male); age 35 ± 14 years) we studied the ECG criteria used to diagnose ARVD/C with specific a focus on TAD. The parameters analyzed were: T wave inversion (TWI) in ≥ V2, TWI ≥ V3, epsilon wave, QRS ≥ 110ms in V1 to V3, parietal block defined as QRSd V1–V6 or V2–V6 or V3–V6 >25 ms in the presence of QRS ≥ 100ms in at least 2 right precordial leads, TAD in V1-V3 and QRSd in V1+V2+V3/V4+V5+V6 ≥ 1.2. Sigma scan software was used for the ECG analysis. Results : In the ARVD/C group, the prevalence of TWI ≥ V2 was 82%, TWI ≥ V3 was 66%, epsilon wave: 1%, QRSd ≥ 110ms V1-V3: 39%, parietal block: 16%, TAD: 46 %, QRSd ratio ≥ 1.2: 19%. In the non cardiac group the prevalence of TWI ≥ V2 was 6 %, TWI ≥ V3: 6%, epsilon wave: 0%, QRSd ≥ 110ms V1–V3: 4%, parietal block: 2%, TAD: 12%, and QRSd ratio ≥ 1.2: 4% (Figure). Conclusion : The results of this study reveal that terminal activation delay has only moderate sensitivity and specificity for the diagnosis of ARVD/C. Our results also reveal that T wave inversion in the right precordial leads is a very sensitive marker of ARVD/C.