What are the atrioventricular delays in right ventricular apical and septal pacing for optimal hemodynamics in...

There is a surge of interest in alternate site pacing to prevent pacing-induced left ventricular dysfunction. However, little is known regarding the appropriate atrioventricular (AV) delay between right ventricular (RV) septal and RV apical pacing for optimal hemodynamic benefit.

To determine the programmed values of atrial sensed and atrial paced AV delays in basal RV septal and apical RV pacing that results in the maximum delivered stroke volume (SV).

We calculated the Doppler-derived SV at various sensed and paced AV delays in 50 patients with complete AV block implanted with a dual-chamber pacemaker (group A: 25 RV apical pacing; group B: 25 RV septal pacing). The hemodynamic difference in terms of the SV between sensed and paced AV delay, corresponding to the site of RV pacing was then compared for statistical significance.

In group A, maximal SV was derived at a sensed AV delay of 123.2 ± 11 ms and paced AV delay of 129.2 ± 10 ms, and in group B, at a sensed AV delay of 123.6 ± 8 ms and paced AV delay of and 132.8 ± 7 ms. At these intervals, there was no difference in the SV between septal and apical RV pacing (P = .28 and .22, respectively).

The atrial sensed and atrial paced AV delays for septal and apical RV pacing for optimal hemodynamics are similar. For optimal hemodynamics, the atrial paced AV delay is longer than the atrial sensed AV delay.