Hemodynamic effects of digoxin on congestive heart failure in old myocardial infarction, dilated cardiomyopathy, acute myocardial infarction and mitral stenosis.

The hemodynamic effects of digoxin (0.01 mg/Kg) on congestive heart failure were compared in 32 patients with old myocardial infarction (OMI) (n = 9), dilated cardiomyopathy (DCM) (n = 10), acute myocardial infarction (AMI) (n = 5) and mitral stenosis (MS) (n = 8). The responses of heart rate (HR) and pulmonary capillary pressure (PCP) to digoxin in OMI, DCM and MS were marked but different in each of these groups and no significant changes were found in patients with AMI. The responses of cardiac index (CI) to digoxin in patients with OMI and DCM in whom left ventricular myocardial contractile force was impaired were divided into 2 groups (Group 1: CI increased more than 15% and Group 2: less than 15%). In Group 1, both CI and percent fractional shortening (%FS) before digoxin administration were lower than in Group 2, i.e., 1.97 +/- 0.27 vs 2.80 +/- 0.48 L/min/m2 (p less than 0.001) and 10.9 +/- 8.0 vs 19.5 +/- 11.9% (p less than 0.05), respectively. In MS, CI increased after digoxin administration only in the 2 patients with low CI and rapid HR in the control state. These results indicate that the mode of hemodynamic response to digoxin is considerably different in various diseases. They further suggest that digoxin should not be used in the early phase of AMI, although digoxin was of great clinical benefit in patients with OMI and DCM through such mechanisms as its positive inotropic and negative chronotropic effects and lowering of PCP.