Sick sinus syndrome and hyperthyroidism: A rare phenomenon

Abstract

Cardiovascular complications play a very crucial part in hyperthyroidism and increased mortality and morbidity risk. Besides tachyarrhythmia, impaired systolic ventricular dysfunction and diastolic dysfunction may cause thyrotoxic cardiomyopathy in a small percentage of the patients, as another high mortality complication. Bradycardia in hyperthyroidism is a rare phenomenon which is associated with the sinus node dysfunction, atrioventricular node dysfunction, and conduction disturbance, or due to the effect of the drugs, i.e. beta-blockers. A 70-year-old female patient was brought to the emergency department with the history of feeling dizziness, lightheadedness, and bradycardia. While waiting in emergency, she had an episode of syncope, followed by regain of consciousness after 20 min. The patient was shifted for pacemaker insertion. Furthermore, hyperthyroidism and sick sinus syndrome are rare phenomena; it is highlighted mainly among patients with Graves' disease.