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 μg/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 the improvement in left ventricular performance were dose-related in mean ventricular pressures, pulmonic and systemic resistances and the lower-frequency components of input impedance moduli. Characteristic impedance and both total 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.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
- Physiology (medical)