Hemodynamic monitoring including assessment of left ventricular filling pressure as pulmonary artery end-diastolic pressure (PAEDP) has been performed in patients with complications of acute myocardial infarction. Important clinical benefits for patient management have accrued from this information. Immediate knowledge of PAEDP is useful in decisions regarding fluid volume and choice of pharmacologic agent in patients with hypotension, cardiogenic shock, or pulmonary edema. Diagnosis of ventricular septal rupture or mitral regurgitation secondary to myocardial infarction depends on right heart catheterization. For patients with prolonged low cardiac output, left ventricular performance can be improved by selecting and maintaining an optimal left ventricular filling pressure. In patients with acute myocardial infarction complicated by heart failure or shock, the clinical usefulness of hemodynamic information justifies pulmonary artery catheterization.