title: Electrophysiologic evaluation and outcome of patients with syncope of unknown origin.
abstract: Electrophysiologic studies were performed in 134 patients (87 males, mean age 59 years) with unexplained syncope. Seventy-one patients had organic heart disease (ischaemic in 50). Electrophysiologic studies revealed conduction abnormalities and tachyarrhythmias that could account for syncope in 40 patients (30%). Thirty-seven (93%) of these patients received pacing or antiarrhythmic therapy compared with 23 (24%) of the remaining 94 patients who had a negative study and received empiric therapy (P less than 0.0001). Risk of having an abnormal electrophysiologic study was greater in patients with underlying heart disease (P less than 0.05). During a mean follow-up of 22 +/- 17 months, 26 patients (19%) either had recurrent syncope (22 patients) or died (four patients) suddenly. Men had a higher incidence of recurrent syncope than women (26% vs 6%, P less than 0.005). Other clinical characteristics, electrophysiologic findings, final diagnosis and therapy at discharge were not predictive of outcome. We conclude that (1) 19% of patients investigated for syncope will have a recurrent event, (2) female gender may be an independent predictor of favourable outcome.
authors.affiliation: Montreal Heart Institute, Canada.
authors.forename: T
authors.initials: T
authors.lastname: Muller
authors.forename: D
authors.initials: D
authors.lastname: Roy
authors.forename: M
authors.initials: M
authors.lastname: Talajic
authors.forename: R
authors.initials: R
authors.lastname: Lemery
authors.forename: S
authors.initials: S
authors.lastname: Nattel
authors.forename: D
authors.initials: D
authors.lastname: Cassidy
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001145:Arrhythmias, Cardiac / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D002304:Cardiac Pacing, Artificial; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000187:drug effects / Q000503:physiopathology*; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D013575:Syncope / Q000209:etiology* / Q000503:physiopathology
chemical_list: D000889:Anti-Arrhythmia Agents