title: The heart rate slowing effect of pindolol in patients with digitalis resistant atrial fibrillation and heart failure.
abstract: 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.
mesh_terms: 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*
chemical_list: D004077:Digoxin; D010869:Pindolol; D008520:Medigoxin