Biventricular pacing doesn't improve left ventricular global systolic or diastolic function but only septal systolic contractility in patients with advanced heart failure and left bundle branch block

Recent studies have shown that biventricular pacing improves left ventricular function on long-term. However, little is known about diastolic function in these patients (pts). This study compared global and segmental systolic and diastolic left ventricular function by gated blood pool technique in 13 pts with advanced heart failure and complete left bundle branch block (BBB) during sinus rhythm, right ventricular (apex) and biventricular pacing. Methods: the mean age was 56 [plusmn] 5 years and 9 pts were male. The mean NYHA functional class was 3.5 [plusmn] 0.8. Analysis during sinus rhythm was done prior to pacemaker implantation. Diastolic function was analyzed according to the peak filing rate (EDV/s) and to the time to peak filling rate milliseconds. The systolic function was analyzed according to segmental and global left ventricular ejection fraction (LVEF). Conclusion: Diastolic function does not change under uni or biventricular pacing as compared to sinus rhythm in pts with advanced heart failure and complete LBBB. Regarding the systolic function, pacing does not improve global LVEF. However, systolic septal contractile function is markedly improved under biventricular pacing as compared to sinus and right ventricular pacing.