Complete Heart Block with Thyrotoxic Myocarditis

Abstract

MANY reports have appeared in the literature of uncomplicated hyperthyroidism associated with prolongation of the PR interval and with transient abnormalities of atrioventricular conduction.1 2 3 4 5 The prevalence varies from series to series, but a fair percentage of patients with thyrotoxicosis have been noted to have these abnormalities.We recently saw a case of complete heart block associated with thyrotoxicosis that was then followed by first-degree heart block and then a normal electrocardiogram. This has been reported only on a few occasions. Davis and Smith6 presented six cases of complete heart block in hyperthyroidism after acute infections, and Steuer7 described a 39-year-old . . .