Optimization of the atrioventricular delay in conduction system pacing.

Introduction: In patients receiving conduction system pacing (CSP), it is not well established how to program the sensed atrioventricular delay (sAVD), with respect to the type of capture obtained (selective, nonselective His‐bundle [HB] capture or left bundle branch [LBB] capture). The aim of this study was to acutely assess the effectiveness of an electrophysiology (EP)‐guided method for sAVD optimization by comparing it with the echocardiogram‐guided optimization. Methods and Results: Consecutive patients undergoing HB or LBB pacing were enrolled. The EP‐guided sAVD was defined as the sAVD leading to a PR interval of 150 ms on surface electrocardiogram (ECG). In HB pacing patients, EP‐guided sAVD was obtained subtracting the time from the onset of the P wave on ECG to the local atrial electrogram (EGM) recorded by the atrial lead (right atrial sensing latency, RASL) and the His‐ventricular interval from 150 ms; in LBB pacing patients, subtracting RASL from 150 ms. Transmitral flow assessment by pulsed wave Doppler was used to find the echo‐optimized sAVD by a modified iterative method. The discordance between the EP‐guided and the echo‐optimized sAVD was recorded. Results: Seventy‐one patients were enrolled: 12 with selective, 32 nonselective HB capture, and 27 LBB capture. Overall, the rate of concordance between the EP‐guided and the echo‐optimized sAVD was 71.8%, with no significant differences between the three groups. Conclusion: In CSP patients, an optimal sAVD can be programmed, in more than 70% of cases, considering only simple EGM intervals to obtain a physiological PR interval on surface ECG. [ABSTRACT FROM AUTHOR]