Does prostaglandin E₁ infusion affect the left ventricular filling pattern of end-stage dilated cardiomyopathy? A combined hemodynamic-echo Doppler study

Prostaglandin E₁ improves hemodynamics in patients with severe dilated cardiomyopathy and pulmonary hypertension through its reducing action on pulmonary resistances. However, few data are available to indicate whether these beneficial effects on right heart hemodynamics translate into any improvement of the altered left ventricular filling pattern that characterizes this condition. We studied 12 patients with dilated cardiomyopathy during preoperative evaluation for cardiac transplantation before and after prostaglandin E₁, 30-50 ng/kg/min i.v. Patients underwent catheterization of the right heart and left ventricle by Swan-Ganz catheter, giving simultaneous assessment of pressure by micromanometer and of volume derived from two-dimensional echo-guided Doppler mitral flow velocity, where volume equals mitral velocity integral x valvular area. Prostaglandin E₁ induced a significant reduction in mean pulmonary (from 38 to 30 mm Hg; p = 0.0001) and aortic (from 79 to 75 mm Hg, p = 0.05) pressures but no change in heart rate or τ. Peak A wave increased from 28 to 33 cm/s (p = 0.02), along with a reduction in end-diastolic pressure from 29 to 26 mm Hg (p < 0.04), whereas peak E wave did not change, E/A ratio decreased slightly (from 2.5 to 2.1; p < 0.0007) but did not reverse. Systolic volumes decreased (from 231 to 212 ml; p < 0.05), and cardiac index increased from 2.1 to 2.6 L/min/m² (p < 0.0002) because of a reduction in pulmonary and systemic vascular resistances. The diastolic pressure-volume relation shifted downward along the same curve. Prostaglandin E₁ infusion in patients with severe dilated cardiomyopathy and pulmonary hypertension reduces pulmonary and systemic resistances without affecting heart rate, relaxation, or passive diastolic left ventricular properties. Systolic right and left ventricular unloading increases cardiac index, facilitating ventricular emptying, E/A ratio does not reverse, although it decreases slightly, with mechanisms, however, that appear independent of any direct effect of the drug on the ventricular diastolic properties.