Reperfusion arrhythmias are rare during acute myocardial infarction and thrombolysis in man.

Coronary arterial reperfusion is commonly associated, in anaesthetized animals, with severe arrhythmias, but the clinical relevance of this model remains uncertain. Continuous electrocardiographic ST-segment recording was performed immediately from admission in 38 patients who presented within six (mean 2.5) hours of the onset of acute myocardial infarction and had emergency coronary arteriography and thrombolysis with intracoronary streptokinase. All patients received high doses of isosorbide dinitrate but no prophylactic anti-arrhythmic drugs. In 19 patients, 36 occurrences of intermittent reperfusion were observed. Stable reperfusion was achieved in 32 patients. Only 14 episodes of arrhythmia (11 ventricular) were observed in 6 patients within five minutes of transient or stable reperfusion. No episodes of arrhythmia were documented within five minutes of the other 57 occurrences of reperfusion. In contrast, 215 episodes of arrhythmia (198 ventricular) not associated with reperfusion were recorded in 32 patients. Arrhythmias are commonly observed in patients during evolving acute myocardial infarction and thrombolysis but are an insensitive and rarely specific marker of reperfusion at the time when this occurs.