The effects of oral hydralazine on right ventricular end-diastolic pressure in patients with right ventricular failure.
Hydralazine reduces pulmonary vascular resistance in patients with primary and secondary pulmonary hypertension, but the effects on right ventricular function of a change in resistance without a reduction in pulmonary arterial pressure are not known. We evaluated the hemodynamic effects of hydralazine, 50 mg, administered orally every 6 hours for 48 hours in 14 patients with right ventricular failure and pulmonary hypertension resulting from various causes. Hydralazine reduced mean right ventricular end-diastolic pressure from 17.4 +/- 5.6 to 11.6 +/- 5.3 mm Hg (p less than 0.001) and increased cardiac output and stroke volume by more than 40%. In nine patients who had no change in mean pulmonary arterial pressure after hydralazine, total pulmonary resistance decreased from 15.9 +/- 6.0 to 10.6 +/- 4.3 (p less than 0.001) and cardiac index increased from 2.07 +/- 0.51 to 2.97 +/- 0.91 (p less than 0.005). There was a close correlation between the reductions in total pulmonary resistance and right ventricular end-diastolic pressure (r = 0.73)). These data suggest that hydralazine can increase cardiac output and reduce right ventricular end-diastolic pressure even when pulmonary arterial pressure remains unchanged.
D000328:Adult; D000368:Aged; D001160:Arterioles / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects*; D002302:Cardiac Output / Q000187:drug effects; D005260:Female; D006333:Heart Failure / Q000188:drug therapy*; D006801:Humans; D006830:Hydralazine / Q000627:therapeutic use*; D006976:Hypertension, Pulmonary / Q000188:drug therapy*; D008168:Lung / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D013318:Stroke Volume / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects
D006830:Hydralazine