Significance of perfusion of the infarct related coronary artery for susceptibility to ventricular tachyarrhythmias in patients with previous myocardial infarction.

OBJECTIVE To study the significance of perfusion of the infarct related coronary artery for susceptibility to ventricular tachyarrhythmias in patients with a remote myocardial infarction. SETTING Tertiary referral cardiac centre. METHODS Angiographic filling of the infarct related artery was assessed in a consecutive series of 85 patients with different susceptibilities to ventricular tachyarrhythmias after previous (> 3 months) Q wave myocardial infarction: 30 patients had a history of cardiac arrest (n = 16) or sustained ventricular tachycardia (n = 14), and sustained ventricular tachyarrhythmia was inducible in these by programmed electrical stimulation (arrhythmia group); 47 patients had no clinical arrhythmic events and no inducible ventricular tachyarrhythmias during programmed ventricular stimulation (control group). Eight patients without a history of any arrhythmic events were inducible into ventricular tachycardia. RESULTS The patients in the arrhythmia group were older (63 (SD 8) years) than the control patients (59 (6) years, P < 0.05), and had larger left ventricular volumes in cineangiography (P < 0.01), but ejection fraction, severity of left ventricular wall motion abnormalities, previous thrombolytic therapy, and time from previous infarction did not differ between the groups. Patients with susceptibility to ventricular tachyarrhythmias more often had a totally occluded infarct related artery on angiography (77%) than patients without arrhythmia susceptibility (21%) (P < 0.001), and complete collateral filling of the infarct artery in cases without complete anterograde filling was less common in the arrhythmia group than in the control group (P < 0.001). Patients without a history of malignant arrhythmia but with inducible ventricular tachyarrhythmia also had no or poor perfusion of the infarct artery more often than the patients without inducible arrhythmia (P < 0.001). Logistic multiple regression showed that no or poor anterograde or collateral filling of the infarct related artery was the most powerful predictor of susceptibility to ventricular tachyarrhythmias (P < 0.001). Left ventricular size and function were not independently related to arrhythmic susceptibility. CONCLUSIONS No or poor angiographic filling of the infarct related artery is closely associated with susceptibility to ventricular tachyarrhythmias late after acute myocardial infarction, suggesting that perfusion of the infarct artery will modify favourably the electrophysiological substrate of the infarct scar independently of the myocardial salvage achieved by early reperfusion.