What is the Brugada syndrome?

The Brugada syndrome is defined as right bundle-branch block and ST-segment elevation (>0.2 mV) in precordial leads (V1 to V3). Patients with the Brugada syndrome have a structurally normal heart but are at an increased risk for syncope and sudden death.

The diagnosis of the syndrome is easily obtained by electrocardiography as long as the patient presents the typical electrocardiographic pattern and there is a history of aborted sudden death or syncopes caused by a polymorphic ventricular tachycardia. It is difficult to forget such a typical electrocardiogram. The ST segment elevation in V1 to V3 with the right bundle branch block pattern is characteristic. The ST changes are different from the ones observed in acute septal ischemia, pericarditis, ventricular aneurysm and in some normal variants like early repolarization. There are though, electrocardiograms which are not as characteristic, and they are only recognized by a physician who is thinking of the syndrome. There are also many patients with a normal electrocardiogram in whom the syndrome can only be recognized a posteriori when the typical pattern appears in a follow-up electrocardiogram or after the administration of ajmaline, procainamide or flecainide. Excellent review of conditions that cause ST elevation other than MI can be found from NEJM (November 2003).