Hemodynamic effects of intravenous digoxin in patients with severe heart failure initially treated with diuretics and vasodilators

The purpose of this study was to assess the hemodynamic effects of intravenous digoxin in patients with New York Heart Association class IV heart failure, who had never previously been treated with digitalis drugs, and who were initially treated only with diuretics and systemic vasodilators to clinical end points of compensation. Eleven male patients, S with idiopathic and 6 with ischemic cardiomyopathy, had sinus rhythm and were hospitalized with congestive heart failure not precipitated by an acute ischemic event. All 11 patients were treated with intravenous furosemide and various vasodilators without invasive hemodynamic monitoring for a mean period of 4.3 ± 2.1 days. This therapy resulted in subjective and objective improvement in all patients as reflected by a significant decrease in heart failure score from 9.5 ± 2.2 to 2.7 ± 2.3 (p < 0.001). When compensation was achieved by clinical criteria, the patients were instrumented and hemodynamics obtained before and serially thereafter for 6 hours after the intravenous administration of digoxin given in two 0.5 mg doses 2 hours apart. In response to digoxin, cardiac index increased from 2.6 ± 0.7 liters/min per m² to a peak of 3.3 ± 0.6 liters/min per m² (p < 0.005); left ventricular stroke work index (g·m/m²) increased from 27 ± 16 to 43 ± 23 (p < 0.005) and the ejection fraction (eight patients) increased from 21 ± 13% to 29 ± 11% (p < 0.04). Mean pulmonary capillary wedge pressure decreased from 24 ± 7 to a minimum of 17 ± 4 mm Hg (p < 0.02). Little hemodynamic improvement was observed after digoxin administration in 5 of the 11 patients. These five patients had a significantly lower pulmonary capillary wedge pressure and higher cardiac index before the administration of digoxin compared with the six responders (p < 0.005 for both variables). It is concluded that although diuretics and systemic vasodilators eliminated most of the clinical signs of heart failure in all of the 11 patients in this study, administration of intravenous digoxin further improved cardiac function in those patients with persistence of abnormal hemodynamic variables.