title: Feasibility of a novel atrioventricular delay optimization method using transmitral and pulmonary venous flow in patients with sequential ventricular pacing or cardiac resynchronization therapy.
abstract: 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.
authors.affiliation: Division of Cardiology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Kenzo
authors.initials: K
authors.lastname: Fukuhara
authors.affiliation: Division of Cardiology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Okura
authors.affiliation: Division of Cardiology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Terumasa
authors.initials: T
authors.lastname: Koyama
authors.affiliation: Division of Cardiology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Teruyoshi
authors.initials: T
authors.lastname: Kume
authors.affiliation: Division of Cardiology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Yoji
authors.initials: Y
authors.lastname: Neishi
authors.affiliation: Division of Cardiology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Hayashida
authors.affiliation: Division of Cardiology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Yoshida
mesh_terms: D001283:Atrioventricular Node; D002304:Cardiac Pacing, Artificial; D058406:Cardiac Resynchronization Therapy; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D006801:Humans; D010138:Pacemaker, Artificial; D013318:Stroke Volume
keywords: AV delay; Cardiac resynchronization therapy; Doppler echocardiography; Left ventricular function; Pacemaker