Haemodynamic effect of dobutamine in cardiac failure (author's transl)

Dobutamine, a new catecholamine with a positive inotropic action, was given by infusion to 9 patients with cardiac failure in a dosage of 5 and 7.5 mug/kg-min over a period of 15 minutes. An improvement of left ventricular function was proven by an increase of cardiac output by 33%, a reduction of end-diastolic pressure from 21 to 14 mm Hg, an improvement of left ventricular ejection fraction from 29 to 39% and of the mean circumferential fibre contraction velocity from 0.4 to 0.8 circ/s. The systolic aortic pressure increased by a mean of 14% (5 mug/kg-min) and 23% (7.5 mug/kg-min). However, the resistance of the systemic circulation decreased from 1858 to 1439 and 1444 dyn-s-cm-5. Cardiac frequency remained unchanged with a dosage of 5 mug/kg-min and increased by a mere 7 beats/min with a dosage of 7.5 mug/kg-min. There was no increased tendency for arrhythmia. Dobutamine thus appears to act relatively selectively on myocardial beta-1 receptors. Results so far indicate therapeutic success in patients with severe cardiac failure, particularly in the low-output syndrome.