The effects of milrinone (Win 47203) on the coronary blood flow and oxygen consumption of the dog heart-lung preparation.
Milrinone is a new bipyridine-positive inotropic agent that is closely related to amrinone. In the nonfailing heart, coronary blood flow was increased and coronary bed resistance was decreased by milrinone, most probably by a direct action of milrinone on the coronary vasculature. Oxygen consumption was increased at the lower workloads. In the failing heart milrinone (0.1 to 0.5 mg/L of blood) increased cardiac output and coronary blood flow and reduced coronary vascular resistance. With the 0.1 mg dose oxygen consumption was reduced, especially at the high workloads, and was not significantly changed at the low work levels. With higher doses of milrinone oxygen consumption of the heart was not changed significantly while external work was increased. These data show that milrinone can increase the work of the heart with a decrease or no significant change in oxygen consumption of the isolated failing heart. The use of this drug in heart failure accompanied by restricted blood flow may thus be indicated.
D000818:Animals; D002302:Cardiac Output / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D006439:Hemodynamics / Q000187:drug effects; D020105:Milrinone; D009206:Myocardium / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects*; D010477:Perfusion; D011728:Pyridones / Q000494:pharmacology*; D013268:Stimulation, Chemical
D011728:Pyridones; D020105:Milrinone