June 1, 1979Open Access
Reduction of early ventricular arrhythmia by acebutolol in patients with acute myocardial infarction.
Key Result
Intravenous acebutolol reduced the frequency of ventricular extrasystoles and repetitive arrhythmias in patients with acute myocardial infarction, without significantly changing infarct size (37 vs 30 CK-gram equivalents).
Structured PICO
Does intravenous acebutolol reduce ventricular arrhythmias and affect infarct size in patients with acute myocardial infarction?
P
Population
72 patients with evolving myocardial infarction, with subsets matched for predicted infarct size or frequency of ventricular extrasystoles.
I
Intervention
Intravenous acebutolol (1-20 mg every 4 hours for 24 hours) beginning 6 hours after the first increase in plasma creatine kinase.
C
Comparator
Controls matched for predicted infarct size (n=25) or frequency of ventricular extrasystoles (n=22).
O
Outcome
Cardiac rhythm (frequency of ventricular extrasystoles and repetitive arrhythmias) and performance (enzymatically estimated infarct size and hemodynamics).surrogate
Intravenous acebutolol safely reduces early ventricular arrhythmias in patients with acute myocardial infarction without adversely affecting hemodynamics or infarct size.
Main Result
Absolute Event Rate: 37% vs 30%
Abstract
To assess the effects of intravenously administered acebutolol (1-20 mg every 4 hours for 24 hours) on cardiac rhythm and performance, we studied 72 patients with evolving myocardial infarction. Twenty-five patients were treated with acebutolol beginning 6 hours after the first increase in the level of plasma creatine kinase. Enzymatically estimated infarct size was compared with that of 25 controls matched for predicted infarct size. Observed infarct sizes were not significantly different in the 2 groups (37 +/- 5 and 30 +/- 5 CK-gram equivalents, respectively). Mean heart rate, diastolic blood pressure, and cardiac output declined from control values during treatment with acebutolol, but remained within the normal range. Mean pulmonary artery pressure and pulmonary artery occlusive pressure were unchanged. In a group of 22 treated patients matched with 22 control subjects for frequency of ventricular extrasystoles, acebutolol effected a prompt reduction in frequencies of ventricular extrasystoles and repetitive arrhythmias, whereas values were not significantly changed in controls during the corresponding intervals. Accordingly, acebutolol may be a useful antiarrhythmic agent in selected patients with acute myocardial infarction with adversely altering haemodynamic stability or enzymatically estimated infarct size.