10-year follow-up of patients with intraventricular conduction defects associated with myocardial infarction: the meaning of QRS duration.
The 10-year survival rate of 66 patients discharged after an acute myocardial infarction associated with intraventricular conduction delay is reported. The whole population under study consisted of 321 patients followed for 10 years or until death. In 46 patients (69.7%) the conduction delay was a definite complication of infarction, in 15 (22.7%) it preceded the acute event and in 5 (7.5%) the time of onset was undetermined. Mortality in the presence of a conduction delay was 74.2% in 10 years vs 39.2% in its absence (p less than .001). Death was sudden in 41.6% of fatalities when a conduction defect was present and 28% in its absence (p less than .01). The 10-year survival was 55% in patients with conduction defects and QRS less than .12 sec duration, 23.8% if QRS was between .12 and .14 sec, and 4% when QRS duration was greater than .14 sec. 72% of patients of this latter group was in NYHA class 3 or 4, whereas 70% of patients with QRS less than .12 sec and 47% of patients with QRS .12 to .14 sec were in class 1 or 2. These data show that long-term prognosis of conduction delay associated to myocardial infarction is poor and stratification of risk of death is possible among these patients on the basis of QRS duration.
D003645:Death, Sudden; D004562:Electrocardiography; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology*; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D009203:Myocardial Infarction / Q000401:mortality* / Q000503:physiopathology; D011446:Prospective Studies