[ST segment elevation, right bundle branch block and sudden death: Brugada's syndrome]

Abstract

Brugada's syndrome is one of the main causes of sudden death in young adults without a structural heart disease. This is an electrical cardiac illness secondary to a mutation of SCN5A gene of chromosome 3 that has a dominant autosomic transmission pattern. This mutation implies the dysfunction of the sodium channel that increases the Ito, loosing the dome of the epicardiac action potential phase two. An "all or none" repolarization pattern ensues and gives rise to a phase two reentry. This kind of reentry is responsible for the initiation and perpetuation of malignant ventricular arrhythmias among these patients. The clinical characteristics of the syndrome are the right bundle branch block, ST segment elevation from V1 to V3 leads and sudden death or syncope. In some patients, a pharmacological test must be done with ajmaline or procainamide to unmask the electrocardiographic changes. At present, the only effective treatment is the implantable cardioverter defibrillator (ICD). This device has the capability to reduce mortality from 40% annually to 0% at ten years. Pharmacological treatment is not useful.