[Influence of post-infarction myocardial revascularization on the prevalence of delayed potentials]

It has been shown that the presence of ventricular late potentials is a predictive factor of ventricular tachycardia and sudden death after myocardial infarction. The value of thrombolysis in the reduction of the prevalence of ventricular late potentials is now well established. However, the effects of other modes of revascularisation is less well known and more controversial. The authors undertook a retrospective study of 139 consecutive patients undergoing coronary angiography after primary myocardial infarction. The presence of ventricular late potentials fulfilling two of the three usual criteria was sought after a revascularisation procedure. The overall prevalence of ventricular late potentials was 30.9%. This was not affected either by the site of infarction of by the single or multiple character of the coronary artery disease. In addition, the left ventricular ejection fraction was not significantly different in patients with positive ventricular late potentials compared with the others. On the other hand, revascularisation of the culprit lesion responsible for the infarction was strongly correlated with a lower incidence of ventricular late potentials (p < 10 (-5)). In particular, the different incidence of positive late potentials between the dilated (9.3%) and non-dilated group (49.2%) was statistically significant (p < 10 (-6)) without any correlation to the single or multiple character of the coronary disease. The authors discuss the different reports in the literature concerning the effects of angioplasty and coronary bypass surgery on the incidence of ventricular late potentials. Conclusion; the review of the literature shows that thrombolysis significantly reduces the incidence of late potentials after myocardial infarction and the present study suggests that angioplasty and coronary bypass surgery may also be effective.