Effects of prostaglandin E₁ on left ventricular performance in dogs; comparisons with trinitroglycerin and adenosine triphosphate

To examine the cardiovascular response to prostaglandin E1 infusion, we observed hemodynamic changes including left ventricular diameter (an ultrasonic crystal pair) during PGE₁-induced hypotension in anesthetized open-chest dogs. Left ventricular contractility was assessed primarily by measuring the slope of the left ventricular endsystolic pressure-diameter relation (ESPDR) determined by combining end-systolic points from a vena caval occlusion. The cardiovascular effects of induced hypotension by infusions of trinitroglycerin and adenosine triphosphate were also examined at the equivalent magnitude of hypotension. Approximately 25% reduction of systemic blood pressure was produced by the three agents. PGE₁ significantly increased cardiac output from 1200 ± 132 to 1439 ± 162 ml·min⁻¹ (mean ± SE, P ≪ 0.05), stroke volume from 9.1 ± 1.1 to 10.0 ± 1.0 ml (P ≪ 0.05), and %-diameter shortening from 10.4 ± 0.8 to 14.4 ± 0.8% (P ≪ 0.01), but the slope of ESPDR was unchanged. Similar changes were also observed during adenosine triphosphate-induced hypotension. PGE₁ significantly decreased end-diastolic diameter in a similar manner to trinitroglycerin. Thus PGE₁ appears to have little influence on left ventricular contractility aside from its effects on afterload and preload, indicating that it is a useful agent for producing controlled hypotension during anesthesia. (Hoka S, Sato M, Okamoto H, et al.: Effect of prostaglandin E₁ on left ventricular performance in dogs; Comparisons with trinitroglycerin and adenosine triphosphate. J Anesth 6: 45–50, 1992)