Abstract 2254: Prevalence of the Brugada-Type ECG and Incidence of Brugada Syndrome in Patients with Sick Sinus Syndrome
OBJECTIVES: We sought to the prevalence of the Brugada-type ECG and the incidence of spontaneous ventricular fibrillation (VF) occurred with the Brugada-type ECG (occurrence of Brugada syndrome) in patients with sick sinus syndrome (SSS).
BACKGROUND: In general population, the prevalence of the Brugada-type ECG is reported as 0.05% to 0.28%. Although a genetic correlation between Brugada syndrome and SSS has been identified, the prevalence of the Brugada-type ECG and incidence of Brugada syndrome in patients with SSS are uncertain.
METHODS: We have studied 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 in our institutions during the period between July 1971 and December 2004. The ECG before an initial PM implantation was examined retrospectively. The Brugada-type ECG was defined as coved type (type 1) and saddleback type (type 2) according to the “Proposed Diagnostic Criteria for the Brugada Syndrome: Consensus Report in 2002”. After device implantation, the occurrence of spontaneous VF or sudden death (SD) was examined in patients with the Brugada-type ECG using the medical records.
RESULTS: The 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 (50%) out of the 4 patients with type 1 ECG had experienced a spontaneous episode of VF 3 and 12 months after the device implantation, respectively. In 10 patients with type 2 ECG, none had VF or SD during the follow-up period of 9.0±6.3 years. 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 (coved type) ECG in SSS patients may be higher compared with the general population. In addition, the incidence of spontaneous VF in SSS patients with the typical Brugada-type ECG seems to be high. We should be careful of recurrent syncope even after PM implantation and recommend upgrading to ICD in SSS patients with typical Brugada-type ECG.