The 32nd International Congress on Electrocardiology (June 4, 2005, Gdansk, Poland )
CLINICA SYMPTOMS AND ELECTROCARDIOGRAPHIC SIGNS OF THE BRUGADA SYNDROME: – JAPANESE EXPERIENCE-
HIRAOKA M, TAKAGI M, YOKOYAMA Y, AIHARA N, AONUMA K & JAPAN IDIOPATHIC VENTRICULAR FIBRILLATION STUDY (J-IVFS) INVESTIGATORS, Tokyo, Japan
The Brugada Syndrome is characterized by ST segment elevation in the right precordial leads (V1-V3) in ECG and development of ventricular fibrillation (VF) in apparently healthy individuals. Thus patients with the Brugada syndrome (BS) have a high risk for sudden cardiac death (SCD). However, clinical characteristics and ECG signs of high risk patients of BS have not been well clarified and, therefore, we carried out the group study to clarify the above questions. A total of 173 cases were enrolled from 50 hospitals throughout Japan during the period of February 2002 and November 2004. A mean age was 53 years old and 166 of 173 cases (95%), were men. The diagnosis of BS was made mainly by the proposed criteria by Wilde et al. All the subjects were divided into three groups according to their clinical presentations;
(1) Asymptomatic Group (A) without any symptoms, 87 cases.
(2) Syncope Group (S) with syncope without documentation of VF, 64 cases.
(3) VF Group (V) with aborted sudden cardiac death with documented VF, 22 cases. We analyzed (1) their clinical characteristics and symptoms, (2) ECG findings, and (3) clinical outcome during the follow-up period. The mean age and male predominance > 90% of the cases were not different among 3 groups. Incidences in family history of SCD were 8~14% without significant differences among 3 groups. Paroxysmal atrial fibrillatrion (AF) was observed with higher incidence in S and V, 28 and 32%, than in A (14%). Coved type ST elevation, Type 1, was associated with 75~82 % of the case and incidences were similar among 3 groups.
Among the measured ECG parameters, r-J intervals in V1 and V2, and QRS duration in V6 of S and V were significantly prolonged compared to those in A. Positive late potentials (LP) of signal averaged ECG were seen in 59~68 % of the examined cases and there were no differences in incidences of positive LP among 3 groups. VF by programmed ventricular stimulation was induced in 81~86 % of the cases and induction rate was not different among 3 groups. Follow-up study was performed to examine the occurrences of cardiac events such as sudden cardiac death or VF for a median period of 15 months in 73 cases. Cardiac events were observed in 4 of 16 cases (25%) with V and 3 of 26 cases (12%) with S, but none in A.
(June 4, 2005, The 32nd International Congress on Electrocardiology, Gdansk, Poland).