Although left ventricular (LV) aneurysm is associated with increased mortality, its independent prognostic significance is controversial. To determine the effect of LV aneurysm on risk, 121 patients with healed myocardial infarction (MI), 55 manifesting akinesia on ventriculography (MI group) and 66 with LV aneurysm characterized by diastolic deformity (eccentricity) and systolic dyskinesia (LV aneurysm group) were studied. At a mean follow-up of 5.7 years, there were 32 cardiac deaths (12 MI vs 20 LV aneurysm), including 9 sudden deaths (1 MI vs 8 LV aneurysm). Multivariate analysis revealed decreasing ejection fraction to be the best predictor of total cardiac death, and revascularization to be protective. Nonsudden cardiac death was predicted by ejection fraction, absence of revascularization and right coronary artery disease, whereas sudden cardiac death was predicted by LV aneurysm and the frequency of ventricular ectopic complexes on Holter monitoring. In the MI group, ejection fraction was the only significant predictor of total cardiac death and nonsudden cardiac death. In the LV aneurysm group, total cardiac death, as well as nonsudden cardiac death, were predicted by ejection fraction, ventricular tachycardia and right coronary artery disease, whereas ventricular tachycardia predicted sudden cardiac death. It is concluded that the risk profile for total cardiac death differs between LV aneurysm and MI patients, and that LV aneurysm constitutes an independent predictor of late sudden cardiac death after MI. Moreover, on a substrate of LV aneurysm, the risk factors for sudden cardiac death and nonsudden cardiac death differ, with ventricular tachycardia being the sole predictor of sudden cardiac death. Furthermore, Holter monitoring is valuable in identifying patients at persistent risk of sudden cardiac death.