Clinical Practice and Cases in Emergency Medicine

Introduction: Brugada syndrome is an important differential diagnosis for unexplained sudden cardiac arrest, particularly in younger patients. The electrocardiographic (ECG) pattern characteristic of Brugada syndrome can be provoked by fever and may vary with changes in body temperature. Therefore, targeted temperature management following cardiac arrest may obscure the distinctive morphology, increasing the risk of misdiagnosis.

Case Report: We report the case of a 44-year-old man who experienced out-of-hospital cardiac arrest due to ventricular fibrillation following influenza B infection. Initial evaluation revealed transient ST-segment elevation in leads V1-V3, while coronary angiography and echocardiographic findings were normal. Although Brugada syndrome was suspected, the diagnosis was deferred because the ECG findings normalized during targeted temperature management at 36°Celsius. However, after completion of temperature management, the patient developed a high-grade fever, accompanied by the emergence of a characteristic coved-type Brugada ECG pattern. Subsequent genetic testing identified a sodium channel protein type 5 subunit alpha mutation return, confirming Brugada syndrome.

Conclusion: Brugada ECG morphology can be affected by core temperature, and repeat electrocardiography during febrile episodes may be informative