Biventricular pacing significantly reduced QT dispersion (73.93 vs 91 ms, p=0.004) and JT dispersion (73.18 vs 100.72 ms, p=0.003) compared to sinus rhythm in patients with severe heart failure.
Does biventricular pacing reduce heterogeneity of ventricular repolarization in patients with severe heart failure?
Biventricular pacing significantly reduces ventricular repolarization heterogeneity compared to sinus rhythm or single-ventricle pacing in patients with severe heart failure, suggesting a potential antiarrhythmic effect.
Absolute Event Rate: 73.93% vs 91%
p-value: p=0.004
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 re-polarization (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 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.
Santangelo et al. (Sun,) conducted a other in Severe heart failure (n=50). Biventricular pacing vs. Sinus rhythm (baseline) was evaluated on QT dispersion (QTd) (p=0.004). Biventricular pacing significantly reduced QT dispersion (73.93 vs 91 ms, p=0.004) and JT dispersion (73.18 vs 100.72 ms, p=0.003) compared to sinus rhythm in patients with severe heart failure.