Prevalence of the Brugada-Type Electrocardiogram and Incidence of Brugada Syndrome in Patients With Sick Sinus Syndrome

Background: In the present study, clarification of the prevalence of the Brugada-type electrocardiogram (ECG) and the incidence of spontaneous ventricular fibrillation (VF) that occurred with the Brugada-type ECG in patients with sick sinus syndrome (SSS) was determined. Methods and Results: A total of 487 consecutive patients (men 45%, mean age 69.9±12.3 years), who were defined as having an indication for cardiac pacemaker (PM) for SSS, were investigated. The ECG before an initial PM implantation and occurrence of VF or sudden cardiac death (SCD) was examined retrospectively. Brugada-type ECG was found in 14 patients (2.87%) including 4 (0.82%) with type 1 and 10 (2.05%) with type 2. During the follow-up period of 7.2±5.4 years, 2 out of the 4 patients with type 1 ECG had experienced a VF episode after the device implantation. In 10 patients with type 2 ECG, none had VF or SCD. The incidence of spontaneous VF (Brugada syndrome) in SSS patients was calculated as 14.1 per 100 person-years with type 1 ECG. Conclusions: The prevalence of typical Brugada-type (type 1) ECG in SSS patients seems to be higher compared with the general population. In addition, SSS patients with the typical Brugada-type ECG might be a high risk for spontaneous VF. (Circ J 2010; 74: 271-277)