Hemodynamic effects of intravenous acebutolol in the acute phase of myocardial infarction

: The haemodynamic tolerance of intravenous acebutolol was evaluated during the acute phase of myocardial infarction. This is a beta-blocker with an intrinsic beta-stimulant effect. The study consisted of 14 patients (10 cases of inferior infarction and 4 cases of anterior infarction) with a mean capillary pressure of less than 20 mmHg and a cardiac index greater than 2 l X min-1 X m-2. The minimal dose of acebutolol was 0.05 mg X kg-1 X h-1 and the maximal dose was 0.125 mg X kg-1 X h-1. The intravenous infusion of acebutolol was commenced between 3 and 12 hours (average: 7.5 hours) after the infarction and was continued for 48 hours, at which time it was replaced by oral administration. The mean total intravenous dose was 409 mg (from 190 to 510 mg). Two patients were excluded from the protocol because of the development of 2nd degree atrioventricular block several minutes after the beginning of the infusion. The basal values of the cardiac index (2.7 l X min-1 X m-2 +/- 0.37), the mean capillary pressure (9.4 mmHg +/- 2.7) and the systolic index (38.3 ml/m2 +/- 6.4) did not change significantly during the infusion, in the 14 patients studied. The double product, heart rate x blood pressure, decreased from the mean basal value of 9,443 to 7,680 at 24 hours and to 7,000 at 48 hours (p less than 0.05). Acebutolol does not depress left ventricular function, provided that it is reserved for patients with class I or II disease according to Killip and Kimball's classification.(ABSTRACT TRUNCATED AT 250 WORDS)