title: Sinus bradycardia in obstructive jaundice--correlation with total serum bile acid concentrations.
abstract: Obstructive jaundice is often listed among the causes of sinus bradycardia. The latter is usually attributed to the effect of bile salts on the sino-atrial node. The purpose of this study was to determine the frequency of sinus bradycardia (heart rate less than 50/min) in 50 patients with severe or moderate cholestasis, and to relate sinus rate and intracardiac conduction to total serum conjugated bile acid concentrations. The latter were measured using a solid-phase 125I radio-immunoassay. The mean sinus rate (+/- SD) in the patients was 74.1 +/- 11.6/min (range 47-100/min). One patient had a sinus rate of less than 50/min and 2 had rates of 50-60/min. The mean total serum conjugated bile acid concentration was 251.1 +/- 198.8 mumol/l (range 13-1000 mumol/l). There was no correlation in individual patients between total serum bile acid concentration and sinus rate (r = +0.097), P-R interval (r = +0.210) or corrected Q-T interval (r = -0.085). We conclude that sinus bradycardia is not a feature of obstructive jaundice and that high serum bile acid concentrations do not exert a slowing effect on the sino-atrial node.
mesh_terms: D000328:Adult; D000368:Aged; D001647:Bile Acids and Salts / Q000097:blood*; D001919:Bradycardia / Q000097:blood / Q000150:complications*; D002779:Cholestasis / Q000097:blood / Q000150:complications*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D001647:Bile Acids and Salts