This presentation has described the modern approach to the patient presenting with chest pain suspected as acute myocardial infarction. Noninvasive and invasive methods have been applied to estimate the extent of the myocardial damage and to monitor the electrical, hemodynamic and metabolic changes during the acute phase. In addition to the use of standard analgesics and antiarrhythmics, measurement of the determinants of left ventricular function by noninvasive and invasive techniques provides a physiologic basis for administration of available pharmacologic agents that can alter the afterload, contractile state, preload, heart rate, metabolic state and infarct size. Information from the Swan-Ganz catheter can describe hemodynamic categories that can be optimally managed by regulation of the left ventricular filling pressure. Patients managed in this manner can be identified for early hospital discharge at 7-10 days. Other patients less than 50 years of age or those experiencing recurrent arrythmias, ischemic pain or evidence of left ventricular dysfunction may be candidates for coronary arteriography and left ventricular angiography before hospital discharge. © 1977.