Which is the Optimal Testing Method for Identifying an AV Delay that Allows Intrinsic Conduction?

Abstract

EGUÍA, L.E., ET AL.: Which is the Optimal Testing Method for Identifying an AV Delay that Allows In trinsic Conduction? It is desirable to maintain normal, conducted ventricular activation in patients with dual-chamber pacemakers and preserved atrioventricular (A V) conduction. The shortest A V delay result ing in consistent ventricular inhibition (avoiding ventricular pseudofusion) was determined by a conven tional incremental (inside-out) technique vs the alternate décrémentai (outside-in) technique in 20 such patients. Determinations were made in VDD mode in 20 patients and DDD mode (-10 beats/min faster than the intrinsic rate) in 19. In VDD mode, the shortest AV delay avoiding ventricular pseudofusion was never found during inside-out testing. It was identical with both methods in 10 patients (50%o), and shorter by 10-80 ms (mean 20 ± 20 ms) with the outside-in method in the remaining 10 (P = 0.004). In DDD mode, the shortest A V delay resulting in consistent ventricular inhibition was found only once during inside-out testing. It was the same with both methods in 13 patients (68%), and shorter by 10-20 ms (mean 14 ± 5 ms) with the outside-in method in the remaining 5 (26%, P = 0.18; Fisher's exact test). The shortest sensed A V delay preventing ventricular pseudofusion is most likely to be found with a décrémentai method (out side-in). In rare patients, it identifies AV delays resulting in inhibition, while ventricular pacing persists at longer programmable AV delays with the conventional inside-out approach. (PACE 2000; 23[Pt. II]:1758-1761 pacemaker, AV delay, sinus node dysfunction, PR interval

Cardiac pacing for bradycardia support: Evidence-based approach to pacemaker selection and programming

“…This strategy should minimize inter-and intraventricular dyssynchrony, increasing cardiac systolic performance. Using a decremental approach (outside-in approach) to finding the longest AV delay where pseudofusion is not present appeared to be an efficient method to achieve this goal [34]. • In the subset of patients with AV block, ventricular capture is unavoidable.…”