[Central and regional vascular hemodynamics of milrinone in experimental heart failure: comparison with captopril and dobutamine].
The present study was designed to evaluate the regional vascular profile of milrinone in the setting of experimental heart failure. Utilizing the rat model of myocardial infarction and failure (average infarct size 28%), we measured cardiac output (CO), arterial pressure (MAP), LVEDP, heart rate and systemic vascular resistance, as well as regional blood flow (radioactive microspheres 15 +/- 5 microns) before and after milrinone i.v. (20 microns/kg bolus, 3 micrograms/kg/min infusion) in the conscious state (LVEDP 22 mm Hg versus 10 mm Hg in the sham-operated group, p less than 0.01). Similarly, central hemodynamics and regional blood flow were determined before and after dobutamine or captopril, administering equipotent doses. Milrinone reduced LVEDP more than dobutamine, both more than captopril; MAP was decreased by captopril only. Although all three drugs reduced SVR to a similar extent and increased CO, a quite different blood flow distribution occurred. Improvement in flow to skeletal muscle and splanchnic circulatory bed was exerted by milrinone only. Thus, milrinone attenuated the vasoconstriction in those circulations known to be impaired in heart failure. In contrast to captopril, the effects of milrinone on renal perfusion were modest. These results demonstrate the potent vasodilator activity of milrinone, which is independent of its direct-positive inotropic effects, being most prominent in the splanchnic, coronary and skeletal muscle circulation. The latter might have clinical relevance since improved muscular flow during exercise is likely to improve exercise capacity in heart failure after long-term treatment.
Drexler
H
H
Medizinische Klinik III, Universität Freiburg.
Faude
F
F
Winterer
H
H
Wollschläger
H
H
Freudenberg
N
N
Just
H
H
D000818:Animals; D002216:Captopril / Q000627:therapeutic use*; D004280:Dobutamine / Q000627:therapeutic use*; D006333:Heart Failure / Q000188:drug therapy*; D006439:Hemodynamics / Q000187:drug effects*; D008297:Male; D020105:Milrinone; D009132:Muscles / Q000098:blood supply; D009203:Myocardial Infarction / Q000188:drug therapy; D011728:Pyridones / Q000627:therapeutic use*; D051381:Rats; D011919:Rats, Inbred Strains; D012039:Regional Blood Flow / Q000187:drug effects; D012079:Renal Circulation / Q000187:drug effects; D012867:Skin / Q000098:blood supply; D013152:Splanchnic Circulation / Q000187:drug effects
D011728:Pyridones; D004280:Dobutamine; D002216:Captopril; D020105:Milrinone
Zentrale und regional-vaskuläre Hämodynamik von Milrinon bei experimenteller Herzinsuffizienz: Vergleich zu Captopril und Dobutamin.