The occurrence of ventricular fibrillation (VF) in the absence of any structural heart disease is classified as

“primary electrical disease” or (in the absence of any relevant findings)“idiopathic VF.” This diagnosis implies that the arrhythmogenic substrate is inherent to the excitable and conducting properties of the heart. With the exception of a positive family history, demographic variables are, as a rule, not very helpful in establishing the diagnosis of primary electrical disease. 1 The paradigm of primary electrical disease is the long-QT syndrome (LQTS), in which altered ionic channel function secondary to mutations in genes encoding ion channels has been shown to underlie QT-interval prolongation. 2, 3

In 1992, Brugada and Brugada4 described 8 patients with a history of aborted sudden death and a distinct ECG pattern, consisting of right bundle-branch block (RBBB) with ST-segment elevation in the right precordial leads (V1, V2, and V3, Figure 1) and normal QT interval in the absence of any structural heart disease (as determined by routine clinical, biochemical, echocardiographic, and angiographic examinations). In 4 of the reported patients, a family history was suspected.