Brugada-Type Electrocardiographic Changes Induced by Fever
A 54-year-old man who was admitted to the hospital with acute cholecystitis developed fever (40°C) and tachycardia. His medical history was significant for hypertension. An ECG revealed sinus tachycardia, incomplete right bundle-branch block, and downsloping (also known as coved-type) ST-segment elevation in leads V1 and V2 (Figure 1) with T-wave inversion, consistent with a type 1 Brugada pattern. His cardiac biomarkers were normal, and these ECG changes resolved completely after resolution of the fever with antipyretic agents. The ECGs performed before (Figure 2) and after (Figures3 and 4) the onset of fever induced the Brugada pattern showed incomplete right bundle-branch block without any Brugada-type changes. Because there was no personal or family history of presyncope, syncope, or sudden cardiac arrest, he was managed conservatively. This patient has done well 2 years after discharge.
The Brugada ECG pattern is characterized by right bundle-branch block and an elevation at the J point that is >2 mm, with a slowly descending ST-segment in conjunction with flat or negative T waves in leads V1, V2, and sometimes V3.1 These ECG changes are often dynamic and can be unmasked by fever, sodium channel blockers, tricyclic antidepressants, cocaine, and electrolyte abnormalities.2 Brugada syndrome is diagnosed when these ECG changes are associated with a personal history of syncope, inducible polymorphic ventricular tachycardia, or ventricular fibrillation or a family history of sudden cardiac death.
Approximately 25% of cases of Brugada syndrome are caused by mutations in the cardiac sodium channel gene SCN5A. The mutated sodium channels result in temperature-dependent ionic changes that cause characteristic Brugada ECG patterns during fever.2
- © 2013 American Heart Association, Inc.