Measurement of the circulatory effects of dobutamine, a new inotropic agent, in patients following cardiac surgery.
The use of an extractable aortic electromagnetic flow probe to provide a continuous on-line display of ascending aortic flow and cardiac output following open heart surgery is described. Utilizing this equipment, the hemodynamic actions of dobutamine and isoprenaline are compared in 14 patients immediately following cardiac surgery. The study confirmed an inotropic action produced by dobutamine at a heart rate 10 to 15 per cent lower than isoprenaline, with less peripheral vascular action. Arterial and coronary sinus blood analyses revealed little difference in the myocardial metabolic actions of either drug. Because inotropic drugs produce only relatively small increases in stroke volume in this group of patients, the rise in cardiac output caused by these agents is more dependent on the effects upon heart rate rather than improved myocardial contractile state and consequently dobutamine has little advantage over isoprenaline in this situation.
D000328:Adult; D001011:Aorta; D002315:Cardiopulmonary Bypass; D002395:Catecholamines / Q000494:pharmacology*; D004280:Dobutamine / Q000494:pharmacology*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects; D012039:Regional Blood Flow / Q000187:drug effects
D002395:Catecholamines; D004280:Dobutamine; D007545:Isoproterenol