Abstract
The hemodynamic effects of dobutamine were compared with those of digoxin in six patients with cardiac failure within 24 hours of onset of acute myocardial infarction. Dobutamine (8.5 μg per kilogram of body weight per minute) was given intravenously for 30 minutes and then discontinued until hemodynamics returned toward base line. Digoxin (12.5 μg per kilogram) was then given intravenously, and hemodynamics were recorded for 90 minutes. Dobutamine decreased left ventricular filling pressure (from 22.3 to 9.8 mm Hg, P<0.02) and systemic vascular resistance (1686±188 to 1259±108 dynes · sec · cm−5), and increased cardiac index (from 2.4 to 3.2 liters per minute per square meter of body-surface area, P<0.005) and stroke work index (from 24.6 to 36.6 g · m per square meter, P<0.02), without changing heart rate or arterial pressure. In contrast, digoxin had no effect on filling pressure (18.3 versus 17.0) and only a slight effect on cardiac index (2.2 versus 2.4, P<0.05) and stroke work index (21.9 versus 27.6, P<0.05). Thus, dobutamine markedly increased cardiac output, decreased filling pressure, and relieved pulmonary congestion. Digoxin did not affect preload or afterload. (N Engl J Med. 1980; 303:846–50.) LEFT ventricular dysfunction resulting in pulmonary congestion is common in patients with acute myocardial infarction.1,2 In patients with symptomatic but mild congestive failure, a diuretic may be adequate. However, in patients with moderate to severe failure, it may be necessary to administer an agent with positive inotropic effect. It is preferable to use an agent with a rapid onset of action and a short half-life. The short half-life is desirable for at least two reasons: if side effects such as enhancement of arrhythmias occur, they can be terminated quickly; and failure associated with infarction is often transient and requires treatment. © 1980, Massachusetts Medical Society. All rights reserved.