Clinical usefulness of head-up tilt test in patients with syncope and intraventricular conduction defect

Head-up tilt test was performed in 99 patients with syncope of unknown orig in and intraventricular conduction defect. Twenty-five per cent had a posit ive response to tilt with reproduction of spontaneous clinical symptoms. Ho lter recording revealed paroxysmal atrioventricular (AV) block in three pat ients. Carotid sinus massage was positive in four patients. An electrophysi ological study was performed in 76 patients with abnormal findings in 17 (2 2%). Thus, vasovagal syncope was the discharge diagnosis in 25 patients (25 %). Therefore, tilt test should be considered in patients with intraventric ular conduction defect presenting with syncope of unknown origin, especiall y if clinical findings suggest the possibility of a vasovagal mechanism, or if the results of the electrophysiological study are inconclusive.