Radionuclide assessment of ventricular function and risk stratification after myocardial infarction.

Prognosis after acute myocardial infarction is determined primarily by left ventricular function and by the extent to which additional coronary obstructions jeopardize viable myocardium. Radionuclide ventriculography is well suited for noninvasive assessments of resting and exercise ventricular function after acute myocardial infarction. The prognostic importance of resting left ventricular function after acute myocardial infarction is well established. Several studies have reported the prognostic utility of submaximal exercise radionuclide ventriculography at the time of hospital discharge. Patients with globally depressed left ventricular function after acute myocardial infarction are at increased risk for cardiac death, while patients with normal resting ventricular function but abnormal function during exercise appear to be at risk for nonfatal ischemic events. The development of gated tomographic techniques and new radiopharmaceuticals will make available more accurate and detailed assessments of ventricular function and combined assessments of function and perfusion. These new developments require further investigation but appear to be promising new techniques with the potential for providing improved assessments of prognosis after acute myocardial infarction.