[Electrophysiological diagnosis of supraventricular tachycardia]

Supraventricular tachycardias are frequent but seldom life-threatening. The role played by electrophysiological exploration in the evaluation of patients is still restricted. The exploration can be performed by the intracavitary or transoesophageal route. The problem is radically different in patients with d atrial arrhythmias or junctional tachycardias, where this exploration aims at determining the degree of atrial vulnerability in the first instance and the exact mechanism of tachycardia in the second. Electrophysiology is indicated principally in junctional tachycardia recurring despite medicinal treatment, when radical ablative therapy is contemplated. In atrial arrhythmias, it is used to study the arrhythmogenic substrate in the forms that resist empirically prescribed treatments and also in young subjects with embolic cerebrovascular accident of unknown origin.