Relatively benign clinical course in asymptomatic patients with Brugada-type electrocardiogram without family history of sudden death

Introduction: The incidence of sudden death or ventricular fibrillation (VF) in asymptomatic Brugada syndrome patients with a family history of sudden death is reported to be very high. However, there are few reports on the prognosis of asymptomatic Brugada syndrome patients without a family history of sudden death. Methods and Results: Eleven patients (all male; mean age 40.5 ± 9.6 years, range 26 to 56) with asymptomatic Brugada-type ECG who had no family history of sudden death were evaluated. The degrees of ST segment elevation and conduction delay on signal-averaged ECG (SAECG) before and after pilsicainide were evaluated in all 11 patients. VF inducibility by ventricular electrical stimulation also was evaluated in 8 of 11 patients. Patients were followed for a period of 9 to 84 months (mean 42.5 ± 21.6). The J point level was increased (V₁: 0.19 ± 0.09 mV to 0.36 ± 0.23 mV; V₂: 0.31 ± 0.12 mV to 0.67 ± 0.35 mV) by pilsicainide. Conduction delay was increased (total QRS: 112.2 ± 6.3 msec to 131.7 ± 6.3 msec; under 40 μV: 42.0 ± 8.5 msec to 52.7 ± 12.7 msec; last 40 msec: 17.4 ± 5.9 μV to 10.4 ± 6.1 μV) on SAECG by pilsicainide. VF was induced in only 1 of 8 patients. None of the patients had syncope or sudden death during a mean follow-up of 42.5 ± 21.6 months. Conclusion: This study suggests that asymptomatic patients with Brugada-type ECG who have no family history of sudden death have a relatively benign clinical course.