Complete Heart Block in Thyrotoxicosis, Is It a Manifestation of Thyroid Storm? A Case Report and Review of the Literature

Abstract

Thyrotoxicosis complicated by advance degree atrioventricular block, a rare complication of a common disease. The term apathetic thyrotoxicosis, where palpitations and cardiac involvement are the sole manifestations of disease, is well known. Thyroxin's ability to sensitize the catecholamine receptors causing tachyarrhythmias is well addressed. However, as an aetiology for advanced heart block, thyrotoxicosis is ranked as one of the rarest.

Atrioventricular block in patients with hyperthyroidism: a narrative review

“…Since the publication of a single case in 1998, 38 multiple reports have described patients with thyroid storm along with various degrees of AVB. 52,[56][57][58] Thyroid storm is a life-threatening endocrine emergency. High clinical suspicion is required to identify patients presenting with thyroid storm.…”

Endocrine causes of heart failure: A clinical primer for cardiologists

“…Atrioventricular block, including complete heart block leading to heart failure have been reported in apathetic thyrotoxicosis. 44 …”

A systematic review of the clinical characteristics and course of atrioventricular blocks in hyperthyroidism

“…Patients are also reported to present with AVBs as the initial manifestation of HTH [ 10–12 ]. Moreover, AVB has been reported to complicate thyroid storm, a life-threatening emergency among patients with HTH [ 13–17 ]. Besides overt HTH, where a patient might be considered sick enough to have other organs involved, AVBs are also reported in subclinical HTH [ 11 ].…”