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 relate d coronary artery for susceptibility to ventricular tachyarrhythmias i n patients with a remote myocardial infarction. Setting-Tertiary refer ral cardiac centre. Methods-Angiographic filling of the infarct relate d artery was assessed in a consecutive series of 85 patients with diff erent susceptibilities to ventricular tachyarrhythmias after previous (> 3 months) Q wave myocardial infarction: 30 patients had a history o f 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 tachyarrhy thmias during programmed ventricular stimulation (control group). Eigh t patients without a history of any arrhythmic events were inducible i nto ventricular tachycardia. Results-The patients in the arrhythmia gr oup were older (63 (SD 8) years) than the control patients (59 (6) yea rs, P < 0.05), and had larger left ventricular volumes in cineangiogra phy (P < 0.01), but ejection fraction, severity of left ventricular wa ll motion abnormalities, previous thrombolytic therapy, and time from previous infarction did not differ between the groups. Patients with s usceptibility to ventricular tachyarrhythmias more often had a totally occluded infarct related artery on angiography (77%) than patients wi thout arrhythmia susceptibility (21%) (P < 0.001), and complete collat eral filling of the infarct artery in cases without complete anterogra de 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 pe rfusion of the infarct artery more often than the patients without ind ucible arrhythmia (P < 0.001). Logistic multiple regression showed tha t no or poor antero-grade or collateral filling of the infarct related artery was the most powerful predictor of susceptibility to ventricul ar tachyarrhythmias (P < 0.001). Left ventricular size and function we re not independently related to arrhythmic susceptibility. Conclusions -No or poor angiographic filling of the infarct related artery is clos ely associated with susceptibility to ventricular tachyarrhythmias lat e after acute myocardial infarction, suggesting that perfusion of the infarct artery will modify favourably the electrophysiological substra te of the infarct scar independently of the myocardial salvage achieve d by early reperfusion.