Left ventricular function and prognosis after myocardial infarction: rationale for therapeutic strategies.

Prognosis after acute myocardial infarction is strongly associated with left ventricular dysfunction. However, asynergy does not necessarily imply loss of viability and myocardial necrosis. In fact, two different patterns of contractile dysfunction, possibly coexisting, have been shown after acute myocardial infarction: Stunning and hibernation represent distinct patterns of contractile dysfunction that share the character of reversibility. It is noteworthy, then, to identify the presence of these two conditions at the bedside and to develop medical treatment to effect recovery of myocardial dysfunction. This strategy has the potential to ameliorate the outcome of patients after acute myocardial infarction by improving left ventricular function. Beta-blocker therapy significantly reduces mortality and the incidence of reinfarction after an acute myocardial infarction: These benefits result from the prevention of sudden death, the reduction of the extent of myocardial injury during the acute phase, and a further antiischemic action. Nevertheless, beta-blocker therapy increases left ventricular dilatation. Recent experimental and clinical data show that ACE inhibitors confer positive therapeutic effects after myocardial infarction by reducing the extent of left ventricular dilation, by reducing mortality, and by improving the clinical outcome. Not all patients, however, can be subjected to this therapeutical approach because of the possible detrimental effects produced by hypotension and by block of neurohormonal activation, sometimes truly compensatory in the early phase. Therefore, it would be interesting to suggest a combination therapy of a beta-blocker with a vasodilator agent (ACE inhibitor or calcium-channel blocker.