Hydralazine therapy in severe chronic heart failure: inability of radionuclide left ventricular ejection fraction measurement to predict the hemodynamic response.

Simultaneous hemodynamic and radionuclide angiographic assessment was made at rest and during exercise in nine patients with severe chronic congestive heart failure to determine the value of radionuclide left ventricular ejection fraction measurement in predicting the hemodynamic response to short-term treatment with oral hydralazine. Hydralazine, 50 to 100 mg orally every 6 hours, produced significant increases in cardiac index and stroke volume index at rest and during exercise (p less than 0.01) and in left ventricular stroke work index at rest (p less than 0.01) and during exercise (p less than 0.05), significant decreases in systemic vascular resistance at rest and during exercise (p less than 0.01) and significant increases in radionuclide angiographic left ventricular ejection fraction at rest (control 0.21 +/- 0.06 vs. hydralazine 0.26 +/- 0.07, p less than 0.01) and during exercise (control 0.21 +/- 0.08 vs. hydralazine 0.24 +/- 0.09, p less than 0.05). However, there were no statistically significant correlations between changes in radionuclide ejection fraction with hydralazine and changes in hemodynamic variables with hydralazine, either at rest or during exercise. Patients responding hemodynamically to hydralazine could not be separated from those not responding on the basis of the radionuclide ejection fraction at rest or changes in ejection fraction with hydralazine.(ABSTRACT TRUNCATED AT 250 WORDS)