Doppler Tissue Imaging Assessment of Left Ventricular Systolic Dyssynchrony in Severe Heart Failure Patients With a Normal QRS Duration

Objectives To assess the prevalence of systolic dyssynchrony of the left ventricular （LV） walls in patients of heart failure（HF） with a normal QRS duration by Doppler tissue imaging （DTI）. Methods 20 patients of HF with a normal QRS duration and 20 healthy individuals were investigated with DTI to quantitatively analyze their pulsed-wave Doppler spectrum of basal and middle segments in six walls of left ventricle. The time between the onset of the QRS complex of the surface ECG and the onset of the systolic wave of pulsed-wave Doppler spectrum was measured （TS）. LV systolic synchronization was assessed by the maximal difference （MD） in time of TS, the standard deviation （SD） and the coefficient of variation （CV） of TS in the all 12 LV segments. Results When a TS-MD of TS〉 53.08 ms, a TS-SD of TS 〉18.08 ms and a TS-CV of TS 〉 0.91 （＋1.65 SD of normal controls） was used to define significant systolic dyssynchrony, the prevalence of systolic dyssynchrony was 55.0 %, 55.0 % and 55.0 %, respectively, in the HF patients group, significantly higher than those in the normal control and the locations of delayed contraction of these patients were different. Conclusions LV systolic dyssynchrony could be commonly demonstrated by DTI in HF patients with a normal QRS duration. This finding will support the view about the possibility that more HF patients could benefit from cardiac resynchronization therapy.

Central aortic systolic blood pressure can better predict prolonged QRS duration than brachial artery systolic blood pressure in rural community residents

Background Central aortic systolic blood pressure（CASP） has been shown to be a stronger predictor of target-organ damage and cardiovascular events than brachial systolic blood pressure（BSBP）, but there was no data about whether CASP can predict prolonged QRS duration more than BSBP. We examined the association of CASP and BSBP with QRS duration in rural community residents. Methods We retrospectively analyzed 490 rural community residents. Standard resting 12-lead ECG and central aortic blood pressure（CABP） were measured noninvasively in all subjects at baseline. The QRS duration was equal to or more than 120 ms being defined as prolonged QRS duration. Results The prolonged QRS duration group showed higher CASP（139.38 ± 11.67 vs. 135.36 ± 16.22, P = 0.031） and BSBP（136.03 ± 6.74 vs. 124.44 ± 13.01, P 〈 0.001） as compared with controls. Multivariate linear regression analysis showed that CASP, BSBP and heart rate were independently affecting QRS duration. Logistic regression analyses showed that CASP（OR 1.057, 95%CI： 1.027, 1.088, P 〈 0.001）and BSBP（OR 1.056, 95%CI： 1.027, 1.086, P = 0.032） were independent predictors of prolonged QRS duration after adjustment for age, sex, body mass index, heart rate. CASP had a better predictive value for prolonged QRS duration than（AUC： 0.793 vs. 0.601, P 〈 0.001） BSBP. Conclusions Our findings demonstrate that both CASP and BSBP are risks for prolonged QRS duration, but CASP can predict prolonged QRS duration better than BSBP.

Left bundle branch pacing vs biventricular pacing in heart failure patients with left bundle branch block:A systematic review and meta-analysis

BACKGROUND Left bundle branch pacing(LBBP)is a novel pacing modality of cardiac resynchronization therapy(CRT)that achieves more physiologic native ventricular activation than biventricular pacing(BiVP).AIM To explore the validity of electromechanical resynchronization,clinical and echocardiographic response of LBBP-CRT.METHODS Systematic review and Meta-analysis were conducted in accordance with the standard guidelines as mentioned in detail in the methodology section.RESULTS In our analysis,the success rate of LBBP-CRT was determined to be 91.1%.LBBP CRT significantly shortened QRS duration,with significant improvement in echocardiographic parameters,including left ventricular ejection fraction,left ventricular end-diastolic diameter and left ventricular end-systolic diameter in comparison with BiVP-CRT.CONCLUSION A significant reduction in New York Heart Association class and B-type natriuretic peptide levels was also observed in the LBBP-CRT group vs BiVP-CRT group.Lastly,the LBBP-CRT cohort had a reduced pacing threshold at follow-up as compared to BiVP-CRT.

Risk of permanent pacemaker implantation following transcatheter aortic valve replacement:Which factors are most relevant?

Transcatheter aortic valve replacement(TAVR)has emerged as a formidable treatment option for severe symptomatic aortic stenosis ahead of surgical aortic valve replacement.The encouraging results from large randomized controlled trials has resulted in an exponential rise in the use of TAVR even in the low-risk patients.However,this is not without challenges.Need for permanent pacemaker(PPM)post-TAVR remains the most frequent and clinically relevant challenge.Naturally,identifying risk factors which predispose an individual to develop high grade conduction block post-TAVR is important.Various demographic factors,electrocardiographic features,anatomic factors and procedural characteristics have all been linked to the development of advanced conduction block and need for PPM following TAVR.Amongst these electrophysiological variables,most notably a prolonged QRS>120 ms regardless of the type of conduction block seems to be one of the strongest predictors on logistic regression models.The index study by Nwaedozie et al highlights that patients requiring PPM post-TAVR had higher odds of having a baseline QRS>120 ms and were more likely to be having diabetes mellitus that those who did not require PPM.

Predictors of permanent pacemaker implantation following transcatheter aortic valve replacement-the search is still on!

Several anatomical,demographic,clinical,electrocardiographic,procedural,and valve-related variables can be used to predict the probability of developing con-duction abnormalities after transcatheter aortic valve replacement(TAVR)that necessitate permanent pacemaker(PPM)implantation.These variables include calcifications around the device landing zone and in the mitral annulus;pre-existing electrocardiographic abnormalities such as left and right bundle branch blocks(BBB),first-and second-degree atrioventricular blocks,as well as bifas-cicular and trifascicular blocks;male sex;diabetes mellitus(DM);hypertension;history of atrial fibrillation;renal failure;dementia;and use of self-expanding valves.The current study supports existing literature by demonstrating that type 2 DM and baseline right BBB are significant predictors of PPM implantation post-TAVR.Regardless of the side of the BBB,this study demonstrated,for the first time,a linear association between the incidence of PPM implantation post-TAVR and every 20 ms increase in baseline QRS duration(above 100 ms).After a 1-year follow-up,patients who received PPM post-TAVR had a higher rate of hospital-ization for heart failure and nonfatal myocardial infarction.

Left bundle branch area pacing:A new era of cardiac resynchronization therapy?

The recent systematic review and meta-analysis provided a comprehensive focus on the current state of cardiac resynchronization therapy(CRT).The authors determined the feasibility of physiological left bundle branch area pacing(LBBAP)in patients indicated for CRT through a careful analysis of trials.They found that LBBAP was associated with significant reductions in QRS duration,New York Heart Association functional class,B-type natriuretic peptide levels,and pacing thresholds as well as improvements in echocardiographic parameters compared to biventricular pacing.

Presence of Fragmented QRS Complexes in Patients with Obstructive Sleep Apnea Syndrome

Background：Obstructive sleep apnea syndrome （OSAS） is a disease with increasing prevalence,which is mainly characterized by increased cardiopulmonary mortality and morbidity.It is well-known that OSAS patients have increased prevalence of cardiovascular diseases including coronary heart disease,heart failure,and arrhythmias.The aim of this study was to evaluate the presence of prolonged and fragmented QRS complexes,which have previously been associated with cardiovascular mortality,in OSAS patients.Methods：Our study included 51 patients （mean age 41.6 ± 10.1 years） who were recently diagnosed with OSAS （apnea-hypopnea index [AHI] ≥5 events/h） and never received therapy.The control group consisted of 34 volunteers （mean age 43.1 ± 11.6 years） in whom OSAS was excluded （AHI 〈5 events/h）.The longest QRS complexes was measured in the 12-lead electrocardiogram （ECG） and the presence of fragmentation in QRS complexes was investigated.Results：Fragmented QRS frequency was significantly higher in patients with OSAS （n =31 [61%] vs.n =12 [35%],P =0.021）.QRS and QTc durations were also significantly longer in OSAS patients than controls （99.8 ± 13.9 ms vs.84.7 ± 14.3 ms,P 〈 0.001;411.4 ± 26.9 ms vs.390.1 ± 32.2 ms,P =0.001,respectively）.Analysis of the patient and controls groups combined revealed a weak-moderate correlation between AHI and QRS duration （r =0.292,P =0.070）.OSAS group had no correlation between AHI and QRS duration （r =-0.231,P =0.203）.Conclusions：In our study fragmented QRS frequency and QRS duration were found to increase in OSAS patients.Both parameters are related with increased cardiovascular mortality.Considering the prognostic importance of ECG parameters,it may be reasonable to recommend more detailed evaluation of OSAS patients with fragmented or prolonged QRS complexes with respect to presence of cardiovascular diseases.