Fever-induced Brugada pattern: How common is it and what does it mean?

BACKGROUND Fever is known to unmask the Brugada pattern on the electrocardiogram (ECG) and trigger ventricular arrhythmias in patients with Brugada syndrome. Genetic studies in selected cases with fever-induced Brugada pattern have identified disease-causing mutations. Thus, "fever-induced Brugada" is a recognized clinical entity. However, its prevalence has not been systematically evaluated. OBJECTIVE The purpose of this study was to assess the prevalence of Brugada pattern in consecutive patients with fever. METHODS ECGs of patients with fever admitted to the emergency department were evaluated for the presence of Brugada pattern and compared with ECGs of consecutive nonfebrile patients. RESULTS ECGs of 402 patients with fever and 909 without were evaluated. Type I Brugada pattern was 20 times more common in the febrile group than in the afebrile group (2% vs 0.1%, respectively, P = .0001). All patients with fever-induced type I Brugada pattern were asymptomatic and remained so during 30 months of follow-up. CONCLUSION Type I Brugada pattern is definitively more common among patients with fever, suggesting that asymptomatic Brugada syndrome is more prevalent than previously estimated.