Objective. The aim of our study was to evaluate the effect of cardiac resyncronization
therapy (CRT) on QT dispersion (QTd), JT dispersion (JTd) and transmural dispersion of repolarization
(TDR), markers of heterogeneity of ventricular repolarization in a study population
with severe heart failure.
Methods and Results. Fifty patients (43 male, 7 female, aged 60.2 ± 3.1 years) suffering from congestive heart failure (N = 39 NYHA class III; N = 11 NYHA class IV) as a result of coronary artery disease (N = 19) or of dilated cardiomyopathy (N = 31), sinus rhythm, QRS duration >130 ms (mean QRS duration >156 ± 21 ms), an ejection fraction < 35%, left ventricular end-diastolic diameter >55 mm, underwent permanent biventricular DDDR pacemaker implantation. A 12-lead standard electrocardiogram was performed at baseline, during right-, left-, and biventricular pacing and QTd, JTd and TDR were assessed. Biventricular pacing significantly reduced QTd (73.93 ± 19.4 ms during BiVP vs 91 ± 6.7 ms at sinus rhythm, p = 0.004), JTd (73.18 ± 17.16 ms during BiVP vs 100.72 ± 39.04 at baseline p = 0.003), TDR (93.16 ± 15.60 vs 101.55 ± 19.08 at baseline; p<0.004), as compared to sinus rhythm. Right ventricular endocardial pacing and left ventricular epicardial pacing both enhanced QTd (RVendoP 94 ± 51 ms, p<0.03; LVepiP 116 ± 71 ms, p<0.02) and TDR (RVendoP 108.13 ± 19.94 ms; p<0.002; LVepiP 114.71 ± 26.1; p<0.05).There was no effect on JTd during right and left ventricular stimulation.
Conclusions. Biventricular pacing causes a statistically significant reduction of ventricular heterogeneity of ripolarization and has an electrophysiological antiarrhythmic influence on arrhythmogenic substrate of dilatative cardiomiopathy. (Heart International 2006; 2: 27-32)
Biventricular pacing, QT dispersion, JT dispersion, TDR, Heart failure
Vincenzo Russo, MD, Via della Resistenza, 48, 80021 Afragola (NA) – Italy, firstname.lastname@example.org
Share this Article
Related Content In Heart Failure
Sodium–glucose Cotransporter 2 Inhibitors’ Rise to the Backbone of Heart Failure Management: A Clinical Review
Heart International. 15(1):Online ahead of journal publication
Heart failure (HF) is an increasingly prevalent clinical syndrome resulting from a variety of disease processes impeding the heart’s ability to effectively circulate blood. With advances in care and a steadily growing and aging population, HF management is becoming a foremost priority in developed nations like the USA, where HF is expected to affect more […]
Ambulatory Management of Worsening Heart Failure: Current Strategies and Future Directions
Heart International. 2021;15(1):Online ahead of journal publication
Heart failure (HF) is a highly prevalent and morbid disease in the USA, imposing a significant burden on patients, hospitals and the health system. The prevalence of HF continues to increase, with over 650,000 new HF cases diagnosed annually.1 There are over 6.2 million people with HF in the USA,2 with an expected increase to 8 million […]
Explaining Sex Differences in Cardiac Resynchronisation Therapy Outcome
European Journal of Arrhythmia & Electrophysiology. 2020;6(1):17-23 DOI: https://doi.org/10.17925/EJAE.2020.6.1.17
Over the past years, several reports have drawn attention to the need to consider sex-specific differences in cardiac resynchronisation therapy (CRT). Most importantly, there is growing concern on the underrepresentation of women in CRT landmark trials which laid the foundation for present guidelines. Patients with symptomatic heart failure, reduced left ventricular ejection fraction (LVEF) ≤35% […]
Journal articles and more to your inbox
Get the latest clinical insights from touchCARDIOSign me up!