Combined hemodynamic echocardiographic Doppler evaluation of prostaglandin E₁ effects in patients with severe dilated cardiomyopathy undergoing evaluation for heart transplantation

Background: Prostaglandin E₁ has been used in patients undergoing evaluation for heart transplantation. Because of high lung metabolism, the drug has been used to test pulmonary vasoreactivity, although a systemic effect is also present. The purpose of this study is a more thorough assessment of the drug. Methods: Prostaglandin E₁ was infused with progressive steps in 14 patients in New York Heart Association class III to IV with severe dilated cardiomyopathy. The patients were studied through a combined hemodynamic and Doppler echocardiographic evaluation. Results: With prostaglandin E₁, mean aortic and pulmonary arterial pressure decreased by 7% (p < 0.01) and 24% (p < 0.001), respectively with a 23% (p < 0.001) increase in stroke volume index. Systemic vascular resistance decreased by 22% (p < 0.001), and pulmonary vascular resistance decreased by 33% (p < 0.001), with a 15% decrease in the pulmonary/systemic vascular resistance ratio. Heart rate was unaffected. Minimum and end-diastolic left ventricular pressure decreased by 35% (p < 0.001) and 21% (p < 0.001), respectively. The logarithmic time constant of left ventricular isovolumetric relaxation and maximum rate of isovolumic pressure decline were not modified. Early and late left ventricle diastolic filling were not significantly modified if considered separately, but there was a 27% (p < 0.01) decrease in the early/late filling ratio, suggesting a redistribution of diastolic filling to later in diastole. The 34% (p < 0.01) decrease in right atrial pressure suggests a reduction in intrapericardial pressure which mirrors the significant change in the curly/late ratio toward a less restrictive filling pattern. Conclusions: It is possible that the end-stage ventricles of these patients respond to the reduction in pulmonary and systemic resistances secondary to prostaglandin E₁ infusion by increasing stroke volume, with a redistribution of diastolic filling to later in diastole.