Figure 2.

The distribution of ventricular arrhythmias; ventricular premature beats (VPBs), ventricular tachycardia (VT) and ventricular fibrillation (VF) during a 25 min occlusion of the left anterior descending coronary artery in anaesthetized dogs; this was followed by rapid reperfusion. Seven of the 12 sham-operated controls fibrillated during the occlusion and all but three had periods of ventricular tachycardia. Only two of these controls survived the combined ischaemia-reperfusion insult. These arrhythmias were markedly suppressed in the paced 24 h group; thus only two dogs fibrillated during the occlusion period and there was a 62% survival from the ischaemia-reperfusion insult. In the paced dogs given aminoguanidine (AG) only one of the nine dogs (i.e. 11%) survived ischaemia and reperfusion. There was no evidence that AG given prior to occlusion in unpaced dogs was pro-arrhythmic.