On the role of ventricular conduction time in rate stabilization for atrial fibrillation.
OBJECTIVE
Ventricular pacing (VP) could stabilize the ventricular rhythm in atrial fibrillation (AF). This study investigates the role of ventricular conduction time (VCT) in rate stabilization for AF.


RESULTS
A novel computer model was used to generate various patterns of RR intervals in AF. For each model configuration, the rate stabilization effect of VP was compared with respect to different VCTs. In all tested cases, the ventricular rate in AF could be stabilized at pacing intervals longer than the shortest spontaneous RR intervals. For each model configuration, slightly longer pacing interval (difference <100 ms) was needed to achieve 95% VP when the antegrade/retrograde VCT was increased from 10/10 to 110/110 ms, whereas the VCT had less effect at lower pacing rate. Although longer VCT was associated with increased percentage of ventricular fusion, its role was diminished at higher pacing rate when more retrograde waves could conduct to the atrium.


CONCLUSIONS
Ventricular conduction time has limited effects on rate stabilization, which could be explained by multi-level interactions between antegrade waves induced by AF and retrograde waves induced by VP.
Lian
Jie
J
Micro Systems Engineering, Inc., 6024 SW Jean Road, Lake Oswego, OR 97035, USA. jie.lian@biotronik.com
Müssig
Dirk
D
Lang
Volker
V
D000818:Animals; D001281:Atrial Fibrillation / Q000503:physiopathology*; D003198:Computer Simulation; D006329:Heart Conduction System / Q000503:physiopathology*; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D008955:Models, Cardiovascular; D013997:Time Factors; D016276:Ventricular Function