Arrhythmia and thyroid dysfunction

Arrhythmia is a major cause of morbidity and mortality in Europe and in the United States. The aim of this review article was to assess the results of the prospective studies that evaluated the risk of arrhythmia in patients with overt and subclinical thyroid disease and discuss the management of this arrhythmia.

A literature search was carried out for reports published with the following terms: thyroid, hypothyroidism, hyperthyroidism, subclinical hyperthyroidism, subclinical hypothyroidism, levothyroxine, triiodothyronine, antithyroid drugs, radioiodine, deiodinase, atrial flutter, supraventricular arrhythmia, ventricular arrhythmia, ventricular tachycardia, ventricular fibrillation, torsade de pointes, amiodarone and atrial fibrillation. The investigation was restricted to reports published in English.

The outcome of this analysis suggests that patients with untreated overt clinical or subclinical thyroid dysfunction are at increased risk of arrhythmia. Hyperthyroidism increased atrial arrhythmia; however, hypothyroidism increased ventricular arrhythmia.

The early recognition and effective treatment of thyroid dysfunction in patients with arrhythmia is mandatory because the long-term prognosis of arrhythmia may be improved with the appropriate treatment of thyroid dysfunction.