Feasibility of a novel atrioventricular delay optimization method using transmitral and pulmonary venous flow in patients with sequential ventricular pacing or cardiac resynchronization therapy

BACKGROUND: Although several echo-Doppler methods were proposed to optimize atrioventricular (AV) delay in patients with sequential ventricular pacing, "echo-guided" AV optimization has not been widely adopted clinically. A combination of trasmitral flow (TMF) and pulmonary venous flow (PVF) measurements may be beneficial to further optimize AV delay to achieve better cardiac function. The aim of this study was to assess the feasibility and usefulness of AV delay optimization by combined use of TMF and PVF. METHODS: A total of 32 patients after sequential ventricular pacemaker implantation were enrolled and studied. The optimal AV delay was defined as the timing to minimize the duration between PVF reversal (a) wave and the duration of the "A" wave of TMF. Stroke volume was measured at the "optimized" AV delay (AVD(OPT)) and was compared with that obtained at shorter (AVD(OPT) - 50 ms) and longer (AVD(OPT) + 50 ms) AV delays. RESULTS: AV optimization was feasible in 27 of 32 patients (87%). Stroke volume at AVD(OPT) was significantly higher than that at shorter or longer AV delay (63 ± 18 ml vs. 57 ± 15 ml vs. 56 ± 16 ml, P = 0.001). CONCLUSIONS: AV delay optimization using TMF and PV flow was feasible. Usefulness of this method requires further investigation with a larger study population.