The Brugada syndrome in Canada: A unique French-Canadian experience

Abstract

B rugada syndrome (BS) involves a cardiac sodium channel abnormality and is associated with a high risk of ventricular arrhythmias and sudden cardiac death in individuals with a structurally normal heart. BS is mainly recognized in the specialized electrophysiology community. Characteristic electrocardiograms (ECGs) show a typical pattern of a right bundle branch block-like complex and ST segment elevation in leads V1 to V3 (1,2). In a recent consensus statement (3), three types of repolarization patterns were recognized: type 1 is diagnostic of BS and is characterized by an elevated, coved ST segment of 2 mm or greater followed by a negative T wave ( Figure 1); type 2 has a saddleback appearance with a high takeoff ST segment elevation of 2 mm or greater followed by an ST elevation of 1 mm or greater and either a positive or a THE QUEBEC HEART INSTITUTE ©2007 Pulsus Group Inc. All rights reserved The Brugada syndrome (BS) is a clinical entity involving cardiac sodium channelopathy, typical electrocardiogram (ECG) changes and predisposition to ventricular arrhythmia. This syndrome is mainly recognized by specialized cardiologists and electrophysiologists. Data regarding BS largely come from multicentre registries or Asian countries. The present report describes the Quebec Heart Institute experience, including the clinical characteristics and prognosis of native French-Canadian subjects with the Brugada-type ECG pattern. METHODS AND RESULTS: BS has been diagnosed in 35 patients (mean age 51±12 years) at the Quebec Heart Institute since 2001. Patients were referred from primary care physicians for ECG abnormalities, syncope or ventricular arrhythmia, or were diagnosed incidentally on an ECG obtained for other purposes. The abnormal ECG was recognized after a syncopal spell in four patients and during family screening in four patients. All of the others were incidental findings following a routine ECG. No patient had a family history of sudden cardiac death at younger than 45 years of age. In this population, right bundle branch block pattern with more than 2 mm ST segment elevation in leads V1 to V3 was recorded spontaneously in 25 patients and was induced by sodium blockers in 10 patients. The sodium channel blocker test was performed in 21 patients and was positive in 18 patients (86%). An electrophysiological study was performed in 20 of 35 patients, during which ventricular fibrillation was induced in five patients; three of the five patients were previously asymptomatic. An implantable cardioverter-defibrillator was implanted in six of 35 patients (17%), including three of four patients with a history of syncope. A loop recorder was implanted in three patients. After a mean follow-up of 36±18 months, one patient died from a noncardiac cause and one patient (with a history of syncope) received an appropriate shock from his implantable cardioverter-defibrillator. No event occurred in the asymptomatic population. CONCLUSIONS: BS is present in the French-Canadian population and is probably under-recognized. Long-...

Outcome of Insertable Cardiac Monitors in Symptomatic Patients with Brugada Syndrome at Low Risk of Sudden Cardiac Death

“…Interestingly, the recent ESC guidelines give a class IIa indication (level of evidence C) for an ICM (instead of an ICD) in Brugada patients with recurrent unexplained syncope who are at low risk of SCD [12]. Currently, there is limited published data on the use of ICM in patients with Brugada syndrome [5,10,11,[16][17][18]. A few case reports in Brugada patients with presumed nonarrhythmogenic syncope have demonstrated the detection of self-terminating sustained ventricular arrhythmia by the ICM [16,17].…”

Prognosis, risk stratification, and management of asymptomatic individuals with Brugada syndrome: A systematic review

“…43 Similar results of low annual incidence of arrhythmic events in asymptomatic patients have been published in several studies so far. [44][45][46][47][48][49][50][51][52][53][54] From the most recent studies, it is evident that the annual incidence of arrhythmic events in asymptomatic individuals with Brugada ECG pattern is about 1%. Arrhythmic events will occur as VF without any warning symptoms in about 50% of cases.…”

Programmed Ventricular Stimulation for Risk Stratification in the Brugada Syndrome

“…The eight included studies comprised 1364 patients, of which participant-level data were provided for all. Since additional patients were enrolled and follow-up extended beyond the publication date in some studies, 20–22 the number of patients in the original publications may differ from those reported here. Follow-up methods in these studies were identical to those reported in the original publications.…”