[Electrophysiologic study in 42 cases of unexplained syncope].

Forty two patients with unexplained syncope underwent intracardiac electrophysiologic study to identify the cause of syncope and to select appropriate therapy. Electrophysiologic abnormalities were demonstrated in 26 patients (62%): sustained ventricular tachycardia in 7 patients (27%) of the abnormal group. His-Purkinje system dysfunction in 4 (15.4%), atrioventricular nodal dysfunction in 4 (15.4%), atrioventricular nodal reentrant supraventricular tachycardia in 2 (7.7%), atrial flutter in 1 (3.8%), sinoatrial nodal dysfunction in 2 (7.7%), carotid sinus hypersensitivity in 3 (11.5%) and hypervagotonia in 3 (11.5%). The results of this study suggest that electrophysiologic study should be considered in patients with unexplained syncope. Electrophysiologic study in an effective method for approaching the diagnosis and improving management of unexplained syncope.