Segmental alterations in left ventricular function are generally present in patients who suffer an acute myocardial infarction. Regional wall motion abnormalities in left ventricular systolic function can be identified in the hyperacute period and generally persist in patients who complete a myocardial infarction. Through the process of infarct expansion, the infarcted territory may thin and lengthen in the short term following a myocardial infarction. Some infarct survivors are also prone to further progressive alterations in the shape and size of the left ventricle, a process that has been termed postinfarction ventricular remodeling. Although left ventricular remodeling appears to represent an adaptive process serving to preserve stroke volume (and cardiac output) following myocardial injury, the enlargement process may have undesirable long-term effects on global left ventricular function and on clinical prognosis. Fortunately, recent experimental and clinical evidence demonstrates that ventricular remodeling and its deleterious consequences may be preventable.