Computer modelling of ventricular rhythm during atrial fibrillation and ventricular pacing

In this paper, we describe a computer model of the ventricular response to atrial fibrillation (AF) in the presence of ventricular pacing (VP). In this model, the AV junction (AVJ) is treated as a lumped structure with defined electrical properties including refractory period and automaticity. The AVJ is randomly bombarded by AF impulses, and can be invaded by the retrograde activation wave induced by the VP as well. The model further incorporates bidirectional conduction delays in both AVJ and ventricle, and the recovery-dependency of the AVJ properties is also considered. Simulations show that dependent upon model parameter settings, multilevel AF-VP interactions may occur to generate various ventricular rhythms that are consistent with experimental observations. This model may be used to study the mechanism of AF-VP interaction and to develop VP-based ventricular rate smoothing algorithms for ventricular rhythm control during AF.