Jasbir S. Sra, MD; Alfred J. Anderson, MS; Shabbir H. Sheikh, MD; Boaz Avitall, MD, PhD; Patrick J. Tchou, MD; Paul J. Troup, MD; Carol J. Gilbert, RN; Masood Akhtar, MD; Mohammad R. Jazayeri, MD
Objective: To determine the clinical characteristics of subgroups of patients with unexplained syncope having electrophysiologic studies and head-up tilt testing and to assess the efficacy of various therapies.
Design: Retrospective study.
Setting: Inpatient services of a tertiary referral center.
Patients: Eighty-six consecutively referred patients with unexplained syncope.
Measurements: All patients had electrophysiologic examinations. Patients with negative results subsequently had head-up tilt testing.
Main Results: Twenty-nine (34%) patients (group 1) had abnormal electrophysiologic results, with sustained monomorphic ventricular tachycardia induced in 72%. Thirty-four (40%) patients (group 2) had syncope provoked by head-up tilt testing. The cause of syncope remained unexplained in 23 (26%) patients (group 3). Structural heart disease was present in 76%, 6%, and 30% of groups 1, 2, and 3, respectively. In group 1, pharmacologic or nonpharmacologic therapy was recommended based on electrophysiologic evaluation. All group 2 patients had negative results on head-up tilt testing while receiving oral beta blockers (27 patients) or disopyramide (7 patients). Group 3 patients did not receive any specific therapy. During a median follow-up period of 18.5 months, syncope recurred in 9 (10%) patients.
Conclusions: The combination of electrophysiologic evaluation and head-up tilt testing can identify the underlying cause of syncope in as many as 74% of patients presenting with unexplained syncope. Therapeutic strategies formulated according to the results of these diagnostic tests appear to prevent syncope effectively in most patients.
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Sra JS, Anderson AJ, Sheikh SH, Avitall B, Tchou PJ, Troup PJ, et al. Unexplained Syncope Evaluated by Electrophysiologic Studies and Head-up Tilt Testing. Ann Intern Med. 1991;114:1013–1019. doi: 10.7326/0003-4819-114-12-1013
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Published: Ann Intern Med. 1991;114(12):1013-1019.
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Print ISSN: 0003-4819 | Online ISSN: 1539-3704
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