The distribution of ventricular arrhythmias following coronary artery occlusion and reperfusion.

<p>This is shown in each individual control dog and in dogs that were infused with sodium nitrite prior to and during the occlusion (NaNO₂-PO group) and 10 min prior to reperfusion (NaNO₂-PR group). The filled coulumns are the times during which the dog was in ventricular fibrillation (VF), the shaded columns show periods of ventricular tachycardia (VT) and the lightly stippled coulumns are periods during which ventricular premature beats (VPBs) were evident. VF on reperfusion is also shown by the black horizontal columns and this was the only arrhythmia assessed during the reperfusion phase. The results show that in the controls VF occurred in 6 dogs and that all the other dogs that survived the occlusion period fibrillated on reperfusion. Thus there were no survival in this group from the combined ischaemia and reperfusion insult. In contrast infusion of sodium nitrite either prior to and during the occlusion or just prior to reperfusion significantly reduced the severity of the occlusion-induced arrhythmias and increased survival on reperfusion. This later was particularly marked in dogs in which sodium nitrite was infused 10 min prior to reperfusion.