Computer modelling of short AV delay dual chamber pacing

A computer simulation model of cardiac rhythm and heart-pacemaker interactions has been used to examine the possibility of short atrial-ventricular (AV) delay DDD pacing to prevent junctional reentry tachycardia. The experiments compared the actions of two pacemaker models: a clinically realistic DDD mode operating with quasi-Wenckebach prolongation of the AV delay, and a modification of the DDD mode which is programmed according to atrial and ventricular refractoriness of the heart and the conduction delays of pathological bypass tracts. The pathological phenomena modeled in the experiments simulate different possibilities of tachycardia initiation. The computational results prove that many possible mechanisms of initiation of junctional reentry tachycardia are beyond the prophylactic capabilities of current sophisticated DDD pacemakers. The results also show that the suggested pacing mode improves antitachycardia prophylaxis even when responding to complex pathological episodes of natural cardiac activity.<>