Exercise stress test unmasking a Brugada pattern in a survivor of cardiac arrest: a case report.

Background: Brugada syndrome (BrS) is a hereditary arrhythmic disorder associated with an increased risk of ventricular arrhythmias (VA) and sudden cardiac death (SCD). Certain triggers may unmask the diagnostic high-risk BrS Type 1 electrocardiographic (ECG) pattern. However, conversion to a Type 1 pattern during peak exercise testing is uncommon. Despite the established benefits of physical activity, exercise in patients with inherited arrhythmia syndromes may provoke malignant arrhythmias. Current guidelines allow for some degree of sports participation in asymptomatic individuals with BrS, including mutation carriers and athletes with only an inducible ECG pattern. Case summary: We describe a case of a young man who survived a cardiac arrest during physical exertion. A treadmill stress test revealed a diagnostic Type 1 BrS ECG pattern at peak exercise. The resting ECG was non-diagnostic, and comprehensive evaluation excluded other causes of cardiac arrest. Discussion: In BrS, VA most commonly occur at rest, during sleep, or during exercise recovery, when vagal tone is predominant. This case demonstrates that BrS Type 1 ECG changes may also be elicited during peak sympathetic stimulation, such as intense exercise. This rare presentation suggests that exercise stress testing could play a role in the diagnostic and risk stratification process in selected patients with suspected BrS. Furthermore, it raises questions regarding the safety of physical activity in this population and whether current recommendations on sports participation warrant re-evaluation in light of such findings.