Sudden death by ventricular fibrillation is a possible complication of most cardiac diseases but there are some cases of ventricular fibrillation assumed to be idiopathic, in which the most complete aetiological investigations remain negative. Syncope and sudden death by torsades de pointe then ventricular fibrillation of long QT syndromes without cardiac disease are well known: they are purely electric abnormalities, the ionic and genetic bases of which are becoming progressively better known. In 1991, a new syndrome was described by Pedro and Joseph Brugada with particular electrocardiographic appearances (right bundle branch block with ST elevation in leads V1-V3) and episodes of ventricular fibrillation occurring in patients without apparent heart disease. This syndrome, clinically similar to the unexpected cases of sudden death during their sleep of young men from South East Asia or living there, has aroused much interest. Similarly to the congenital long QT syndrome, the concept of a purely arrhythmic abnormality seems apparent and our understanding of the sequence leading from the electrocardiographic changes to the underlying ionic abnormalities initiating them and the genetic disorders which program them, have made great strides.