Effects of Ouabain on Impaired Left Ventricular Function during Convalescence after Acute Myocardial Infarction

The effects of intravenous ouabain (0.015 mg/kg body weight) were assessed in 13 patients 3-5 weeks after an uncomplicated acute myocardial infarction. The patients were not in clinical cardiac failure and were not having anginal pain. The mean ± sem of the values prior to (C) and 1 hour after ouabain (A) were: left ventricular end-diastolic pressure (LVEDP), C 18.6 ± 1.5, A 10.2 ± 1.4; stroke index, C 35.8 ± 3.9, A 39.5 ± 4.8; left ventricular stroke work (LVSW), C 99.4 ± 15.8, A 120.3 ± 19.5; mean rate of LV ejection (MRE), C 237.3 ± 21.9, A 274.5 ± 28.9; peak LV dp/dt, C 1,614 ± 141, A 2,145 ± 230; preejection period corrected for heart rate (PEP c ), C 135.8 ± 8.7, A 125.1 ± 9.2; left ventricular ejection time corrected for heart rate (LVET C ), C 407.9 ± 10.3, A 389.5 ± 9.2. These changes were significant ( P < 0.05 for paired determinations). There were no significant changes in cardiac index, heart rate, mean arterial pressure, and systemic resistance. The reductions of LVEDP, PEP c , and LVET c and increases in SI, LVSW, MRE, and peak LV dp/dt show improvement of ventricular performance after ouabain and suggest that digitalis therapy could contribute to the management of patients convalescing after uncomplicated acute myocardial infarction.