Sodium Nitroprusside Therapy in Congestive Cardiomyopathy—Variability in Hemodynamic Response

Abstract

Of 17 patients (group A) with congestive cardiomyopathy, 12 improved hemodynamically during sodium nitroprusside (NP) infusion. Five patients (group B) failed to increase their cardiac output. The 2 groups were identical in clinical presentation and had comparable cardiomegaly and left ventricular filling pressure (LVFP). Group A had a baseline cardiac index (CI) lower than 2.5 l/min per m2 and high peripheral systemic (PSR) and total pulmonary vascular resistance (PR). In contrast, group B had a control of CI of higher than 2.5 l/min per m2 and near normal PSR and PR. A highly significant correlation was observed between the calculated levels of control PSR and their subsequent reduction during NP infusion. NP infusion may not increase cardiac output in congestive cardiomyopathy, in spite of a high LVFP, if the PSR is near normal.