The heart rate slowing effect of pindolol in patients with digitalis resistant atrial fibrillation and heart failure.
Heart rate (HR) slowing action and the possible negative inotropic effect of pindolol (P) (daily dose +/- standard error of the means (SEM): 14.7 +/- 1.6 mg) were studied in 12 patients with heart failure and with rapid atrial fibrillation (AF) resistant to effective beta-methyl dioxin (BMD) doses (mean plasma digoxin concentration +/- SEM: 2.05 +/- 0.17 ng/ml). Mild bicycle ergometer exercise test with the same work load was performed under both BMD and combined BMD--P therapy. Rest exercise and 5 minute recovery HR were significantly lower under combined BMD--P therapy than under BMD alone (80.8 +/- 3 vs. 101 +/- 4.5 beats/min, 123.8 +/- 3.9 vs. 155.8 +/- 7.6 beats/min and 84.9 +/- 2.6 vs. 105.1 +/- 4.5 beats min respectively, p less than 0.001, paired t test). Differences in cardiac volume were not significant (1.131 +/- 76 vs. 1.116 +/- 92 ml). Although all patients were clinically improved under combined BMD--P therapy the 13 to 14% increase in cardiac volume noted in 3 cases could be related to some negative inotropic effect of P. It is concluded that in patients with heart failure and with rapid AF resistant to digitalis, the association of P to digitalis is effective in rest- and mild-exercise HR control without a clinically expressed negative inotropic effect.
D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000188:drug therapy*; D003864:Depression, Chemical; D004077:Digoxin / Q000031:analogs & derivatives*; D004351:Drug Resistance; D005260:Female; D006333:Heart Failure / Q000188:drug therapy*; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D008520:Medigoxin / Q000627:therapeutic use*; D008875:Middle Aged; D010869:Pindolol / Q000627:therapeutic use*
D004077:Digoxin; D010869:Pindolol; D008520:Medigoxin