Effect of nitroprusside on hydraulic vascular loads on the right and left ventricle of patients with heart failure.
We studied the effect of nitroprusside on the hydraulic vascular load of the right and left ventricle in seven patients with severe left ventricular failure. At doses of 0.25-0.75 micrograms/kg/min, stroke volume increased progressively from 40.1 to 48.6 ml and left ventricular end-diastolic pressure decreased from 24.5 to 11.2 mm Hg. Accompanying this improvement in left ventricular performance were dose-related decreases in mean ventricular pressures, pulmonic and systemic resistances and the lower-frequency components of input impedance moduli. Characteristic impedance and both total and oscillatory external power were decreased in the pulmonic, but not the aortic, vasculature. In this class of patients, right ventricular unloading is a striking and direct effect of nitroprusside and may account, in part, for improved left ventricular performance through ventricular interdependence.
D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D005292:Ferricyanides / Q000627:therapeutic use*; D006333:Heart Failure / Q000188:drug therapy*; D006352:Heart Ventricles; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects; D009599:Nitroprusside / Q000008:administration & dosage / Q000627:therapeutic use*; D013318:Stroke Volume / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects; D014665:Vasodilator Agents / Q000627:therapeutic use
D005292:Ferricyanides; D014665:Vasodilator Agents; D009599:Nitroprusside