Left ventricular dilatation following myocardial infarction: clinical course and potential for therapy.

The enlarged heart has long been recognized as an important sign of systolic dysfunction of many different etiologies. Regardless of etiology, cardiac enlargement is associated with decreased survival. Cardiac enlargement after acute myocardial infarction (AMI) may be a progressive process. Early after AMI, the process of infarct expansion, or thinning and stretching of the infarct region leads to early volume enlargement detectable within 3 days of the infarct. During the next 2 weeks, volume enlargement takes place which includes lengthening of both the infarcted and the non-infarcted regions. Finally, additional left ventricular enlargement occurs during the next year after the infarction. Both experimental and clinical studies have demonstrated that such progressive LV enlargement may be halted by angiotensin converting enzyme inhibition with captopril. A large scale randomized trial is currently under way to determine whether captopril improves survival after infarction (Survival and Ventricular Enlargement, SAVE).