The value of electrophysiologic studies in syncope of undetermined origin: report of 150 cases
Short Title: 
The value of electrophysiologic studies in syncope of undetermined origin

A prospective study examined the diagnostic yield and therapeutic efficacy of electrophysiologic studies in patients with SUO. We defined SUO as those syncopal or near-syncopal events remaining unexplained after a standardized, noninvasive evaluation that included a history, physical examination, routine laboratory screening, EEG, nuclear brain scan or CAT scan, 12-lead ECG, chest x-ray, orthostatic vital signs, bedside carotid sinus massage, and at least 24 hours of continuous ECG monitoring. The 150 SUO patients included 95 men and 55 women (mean age 62.0 years); 35 had recurrent SUO, 75 (50%) had organic heart disease, and 129 (86%) had abnormal ECGs. There were 162 abnormal electrophysiologic findings that could explain the SUO uncovered in 112 patients, a diagnostic yield of 75%: one finding in 71 patients, two findings in 32, and three findings in nine. These findings were: His-Purkinje disease in 49 patients (30%), inducible ventricular arrhythmias in 36 (22%), AV nodal disease in 20 (12%), sinus node disease in 19 (12%), inducible supraventricular arrhythmias in 18 (11%), carotid sinus hypersensitivity (not elicited by carotid sinus massage prior to electrophysiologic studies) in 15 (9%), and hypervagotonia in five (3%). When electrophysiologic study findings were classified as clearly abnormal or borderline, 54 patients had at least one clearly abnormal finding, a diagnostic yield of 36%. Subgroups of patients presenting with only a single SUO event, no evidence of organic heart disease, or normal baseline ECGs all had substantial diagnostic yields during electrophysiologic studies. Follow-up data in 137 patients (91%) (mean 31 months) showed recurrences in 16 of 34 patients (47%) without and 15 of 103 patients (15%) with electrophysiologic findings despite therapy directed by electrophysiologic testing (p less than 0.0005). This study and a review of the literature indicate that electrophysiologic testing is useful in elucidating the causes of SUO and directing therapy. A significant number of patients benefit from electrophysiologic studies, even when only clearly abnormal findings are considered diagnostic, when only a single syncopal event has occurred, or whether or not organic heart disease or an abnormal ECG is present.

Teichman, S. L.
Felder, S. D.
Matos, J. A.
Kim, S. G.
Waspe, L. E.
Fisher, J. D.
Item Type: 
Journal Article
Publication Title: 
American Heart Journal
Journal Abbreviation: 
Am. Heart J.
Publication Date: 
Aug 1985
Publication Year: 
Library Catalog: 
NCBI Published Medical (?)
PMID: 4025122

Turabian/Chicago Citation

S. L. Teichman, S. D. Felder, J. A. Matos, S. G. Kim, L. E. Waspe and J. D. Fisher. Aug 1985. "The value of electrophysiologic studies in syncope of undetermined origin: report of 150 cases." American Heart Journal 110: 2: 469-479.

Wikipedia Citation

<ref> {{Cite journal | doi = | issn = 0002-8703 | volume = 110 | pages = 469-479 | last = Teichman | first = S. L. | coauthors = Felder, S. D., Matos, J. A., Kim, S. G., Waspe, L. E., Fisher, J. D. | title = The value of electrophysiologic studies in syncope of undetermined origin: report of 150 cases | journal = American Heart Journal | date = Aug 1985 | pmid = | pmc = }} </ref>