Unusual Manifestation of Graves’ Disease: Ventricular Fibrillation

Background: It is well known that thyrotoxicosis causes rhythm disorders including sinus tachycardia, atrial fibrillation, and atrial flutter. Atrial fibrillation is the most common arrhythmia in thyrotoxicosis, occurring in 5–15% of patients over 60 years of age, whereas ventricular arrhythmia is an unusual manifestation. Case Report: An 18-year-old Japanese woman was admitted to our emergency department because of loss of consciousness caused by ventricular fibrillation. She had been diagnosed with Graves’ disease only 5 days earlier and had no other past medical history. Blood examination showed no obvious abnormality except thyroReceived: March 19, 2015 Accepted after revision: June 25, 2015 Published online: August 26, 2015 Akira Haketa, MD Division of Nephrology, Hypertension and Endocrinology Department of Internal Medicine, Nihon University School of Medicine 30-1 Oyaguchi Kami-chou, Itabashi-ku, Tokyo 173-8610 (Japan) E-Mail haketa07 @ gmail.com © 2015 European Thyroid Association Published by S. Karger AG, Basel 2235–0640/15/0043–0207$39.50/0 www.karger.com/etj What Is Known about This Topic? • Thyrotoxicosis is associated with an increased risk of arrhythmia, especially supraventricular arrhythmias. What Does This Case Report Add? • This case suggests that thyrotoxicosis can cause ventricular fibrillation even in the absence of hypokalemia, heart failure, or underlying cardiovascular disease. D ow nl oa de d by : 54 .7 0. 40 .1 1 11 /2 0/ 20 17 7 :5 1: 06 A M