Outcome of primary coronary recanalization and arrhythmia profile in survivors of acute myocardial infarction.

The purpose of this study was to assess the arrhythmia profile in survivors of acute myocardial infarction in whom recanalization of the infarct-related vessel was attempted. 127 patients with acute myocardial infarction were randomized to intravenous and intracoronary thrombolysis with or without transluminal coronary angioplasty. 84 of them, aged 54 +/- 9 years, had angiographic control, 24-hour Holter electrocardiographic monitoring and programmed electrical stimulation 4 weeks after infarction. The study protocol of programmed electrical stimulation included single and double extrastimuli at 2 driving cycle lengths. The end point was the induction of ventricular tachycardia with 10 and more beats. During infarction 28 patients had occlusion of the left anterior descending, 12 of the circumflex and 44 of the right coronary artery. Holter monitoring revealed both frequent (greater than 100 ventricular premature complexes per 24 hours) and repetitive (Lown IVA, IVB) ventricular arrhythmias in 23 patients (27%). Inducible ventricular tachycardia (greater than 6 beats) was found in 25 patients (30%), which was sustained in 4 patients. According to the angiographic results two groups of patients could be identified: group A consisted of 64 patients who showed primary recanalization of the infarct-related vessel with persistent patency at control. Group B consisted of 20 patients who showed late reopening (n = 5) or a closed infarct-related vessel (n = 15) due to late reocclusion in 9 of them. Frequent ventricular premature contractions occurred in 18 group A and in 5 group B patients (n.s.). Repetitive ventricular premature contractions were found in 21 group A and in 2 group B patients (P less than 0.05). Inducible ventricular tachycardia was observed in 17 patients of group A (27%) and in 8 patients of group B (40%) (n.s.). The incidence of spontaneous and stimulus-induced ventricular arrhythmias was not influenced by the type of recanalization procedure. Furthermore no relation to the time interval between onset of preinfarct angina and angiographically demonstrated reperfusion of the infarct-related vessel was found. The patients in the two groups did not differ with respect to left ventricular ejection fraction, number of abnormal contracting wall segments or site of infarction. It is concluded that reperfusion infarction does not differ from infarction due to permanent occlusion with respect to inducible ventricular tachycardia but may favor repetitive ectopic activity.