VENTRICULAR PREMATURE BEAT-DRIVEN INTERMITTENT RESTORATION OF CORONARY BLOOD-FLOW REDUCES THE INCIDENCE OF REPERFUSION-INDUCED VENTRICULAR-FIBRILLATION IN A CAT MODEL OF REGIONAL ISCHEMIA

With a cat model of regional cardiac ischemia, we examined whether the incidence of reperfusion-induced ventricular fibrillation (VF) could be reduced by ventricular premature beat (VPB)-driven intermittent rep erfusion. In addition, we assessed whether the effect of the intermitt ent reperfusion was comparable with that df ischemic preconditioning i n suppressing the VF. Of 15 cats subjected to uninterrupted reperfusio n after 20-minute occlusion of the left anterior descending coronary a rtery, 13 (85.7%) had VF, whereas only 1 (7.1%) of 14 cats subjected t o the VPB-driven intermittent reperfusion had VF. This incidence of Vf was significantly lower than that of the animal group subjected to un interrupted reperfusion. However, it was not statistically different f rom that (3 of 15) of the group subjected to a 10-minute episode of th e coronary artery occlusion before the 20-minute occlusion (i.e., ''is chemic preconditioning''). Our results suggest that the VPB-driven int ermittent reperfusion (i.e., ''postconditioning'') is very effective i n preventing reperfusion-induced VF and as good as, if not better than , ischemic preconditioning.