Brugada Syndrome: A Major Cause of Sudden Cardiac Death
In 1992 a new syndrome was described consisting of syncopal episodes or sudden death in patients with a structurally normal heart and an electrocardiogram characteristic of right bundle branch block with ST segment elevation in leads V1 to V3. Brugada syndrome is an autosomal dominant disorder. It has been shown to be associated with mutations in the gene (SCN5A) that encodes for the sodium ion channel in cardiac myocyte. Over 160 mutations of gene SCN5A have been identifi ed. The incidence of the disease is diffi cult to estimate, but it causes sudden deaths of 5 per 10,000 inhabitants per year and involved much more frequently
in people of Asian ancestry. Diagnosis can be easily made by means of genetic analysis and ECG. Recent data suggest that loss of the action potential dome in the right ventricular epicardium underlies ST segment elevation seen in this syndrome. Right ventricular epicardium is preferentially aff ected because of the predominance of transient outward current in this tissue. Antiarrhythmic drugs like amiodarone and beta-blockers do not prevent death in symptomatic or asymptomatic individuals. Though Implantation of an
automatic cardioverter–defibrillator is the only recently proven eff ective therapy; Quinidine has been found to decrease Ventricular fibrillation and could prove to be a secured option of implantable cardioverter–defi brillator. However, researcher set focus on gene therapy that may off er an enduring cure in future years. The purpose of this brief review is to record the past highlights that have brought us to our present understanding of Brugada syndrome.