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

Asymptomatic Brugada-Type ECG. 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 pa tients 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 hist ory of sudden death were evaluated. The degrees of ST segment elevation and conduction delay on signal-averaged ECG (SAECG) before and after pilsicain ide were evaluated in all 11 patients. VF inducibility by ventricular elect rical stimulation also was evaluated in 8 of 11 patients. Patients were fol lowed for a period of 9 to 84 months (mean 42.5 +/- 21.6). The J point leve l was increased (V-1: 0.19 +/- 0.09 mV to 0.36 +/- 0.23 mV; V-2: 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 30 muV: 42.0 /- 8.5 msec to 52.7 +/- 12.7 msec; last 40 msec: 17.4 +/- 5.9 muV to 10.4 /- 6.1 muV) on SAECG by pilsicainide, VF was induced in only 1 of 8 patient s. 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-typ e ECG who have no family history of sudden death have a relatively benign c linical course.