The syndrome of right bundle branch block, ST segment elevation in V1 to V3 and sudden death is a clinical-electrocardiographic diagnosis based on syncopal or sudden death episodes in patients with a structurally normal heart with a characteristic electrocardiographic pattern: The electrocardiogram shows ST segment elevation in the precordial leads V1 to V3, with a morphology of the QRS complex resembling a right bundle branch block (picture 1). This pattern of right bundle branch block has also been called J point elevation.

picture 1
Typical electrocardiogram of Brugada syndrome.
Note the pattern resembling a right bundle branch block,
the P-R prolongation and the ST elevation in leads V1-V3.

The episodes of syncope and sudden death (aborted or not) are caused by fast polymorphic ventricular tachycardias or ventricular fibrillation (picture 2). These arrhythmias appear with no warning. There is no prolongation of the QT interval during sinus rhythm. Only in very few cases there is alternation of long-short sequences before the polymorphic ventricular tachycardia, a finding which is very common in other arrhythmias like "torsade de pointes" in the long QT syndrome. There is no preceding acceleration in the heart rate as is the case of cathecolamine-dependent polymorphic ventricular tachycardia

picture 2
Spontaneous polymorphic ventricular tachycardia recorded
during monitoring in a patient with Brugada syndrome.
The arrhythmias are fast and need DC shock to terminate.