Left ventricular hemodynamics and function in acute myocardial infarction: studies during the acute phase, convalescence and late recovery.

The left ventricular hemodynamics of 70 patients with acute myocardial infarction were determined from measurements of pulmonary arterial end-diastolic pressure, cardiac index, mean arterial pressure and heart rate during the acute phase(first study, 5 hours after admission), 4 to 6 weeks later (second study, during convalescence) and in 35 percent of all subjects 6 to 12 months after the acute infarction (third study). Serial analysis of serum creatine kinase was carried out during the acute phase. The peak CK value normalized for body surface area was used as a rough index of the extent of the acute myocardial necrosis. The condition of all survivors of the acute stage improved. Patients with only slightly reduced left ventricular performance during the acute stage recovered to nearly normal during convalescence. The condition of patients with greatly reduced left ventricular function also improved but remained impaired during convalescence. In all patients the main changes in left ventricular hemodynamics occurred within the first 4 to 6 weeks; there was almost no further alteration during the following 9 months.