The importance of load-independent analysis in assessment of the inotropic effect of prostaglandin E1 in vivo.
Load-independent pressure-dimension analysis was applied in 13 open-chest, anesthetized dogs during either left atrial (n = 7) or right atrial (n = 6) infusion of prostaglandin E1. Right atrial infusion of prostaglandin E1 in doses from 31 to 500 ng/kg/min resulted in no change in any parameters studied, including mean arterial pressure, cardiac output, and systemic and pulmonary vascular resistances. Left atrial infusion of prostaglandin E1 produced dose-dependent reductions in mean arterial pressure and systemic vascular resistance but no change in the slope of the relationship of left ventricular stroke work to end-diastolic length, a load-independent index of ventricular performance. In contrast to findings obtained with load-dependent parameters, these results suggest that prostaglandin E1 has no positive inotropic effect in vivo.
Brunsting
L A
LA
Department of Surgery, Duke University Medical Center, Durham, NC 27710.
Salter
D R
DR
Murphy
C E
CE
Abd-Elfattah
A S
AS
Goldstein
J P
JP
Wechsler
A S
AS
D000818:Animals; D004285:Dogs; D006439:Hemodynamics / Q000187:drug effects*; D009200:Myocardial Contraction / Q000187:drug effects*; D011458:Prostaglandins E / Q000494:pharmacology*
D011458:Prostaglandins E