Usefulness of a non-invasive scoring system in predicting the outcome of electrophysiologic studies in non-invasively unexplained syncope.
BACKGROUND
An electrophysiologic study is a useful method to clarify the cause of non-invasively unexplained syncope in 18-60% of patients. However, it is invasive with possible procedure-related complications. Therefore, it would be helpful to identify patients in whom an electrophysiologic study is useful for diagnosis of syncope.


METHODS
Patients with unexplained syncope were prospectively enrolled in a registry, if an electrophysiologic study was performed. The study group comprised of 643 consecutive patients.


RESULTS
The electrophysiologic study revealed conduction abnormalities and tachyarrhythmias accounting for syncope in 35% of patients. Using a logistic regression model, history of injury during syncope (p<0.001), ejection fraction < or =40% (p=0.03), and PR interval >0.2 s (p=0.001) were independent predictors of an abnormal electrophysiologic study. These three clinical and easily measurable variables were entered into a scoring system. The maximal score consisted of 3 points. A score of >1 predicts a positive electrophysiologic study result in more than 70% of patients with non-invasively unexplained syncope.


CONCLUSIONS
Electrophysiologic abnormalities were detected in 35% of patients with unexplained syncope. A history of injury, ejection fraction < or =40% and a PR interval >200 ms were independent predictors for a positive electrophysiologic study.
Seidl
K
K
Herzzentrum Ludwigshafen, Kardiologie, Bremserstr. 79, 67063 Ludwigshafen, Germany. seidlk@klilu.de
Drögemüller
A
A
Rameken
M
M
Zahn
R
R
Schneider
S
S
Senges
J
J
D000328:Adult; D000368:Aged; D001283:Atrioventricular Node / Q000503:physiopathology; D001919:Bradycardia / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D002036:Bundle of His / Q000503:physiopathology; D002037:Bundle-Branch Block / Q000175:diagnosis / Q000503:physiopathology; D002303:Cardiac Output, Low / Q000175:diagnosis / Q000503:physiopathology; D002304:Cardiac Pacing, Artificial; D003937:Diagnosis, Differential; D004562:Electrocardiography; D005260:Female; D006327:Heart Block / Q000175:diagnosis / Q000503:physiopathology; D006331:Heart Diseases / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012042:Registries; D012849:Sinoatrial Node / Q000503:physiopathology; D015996:Survival Rate; D013575:Syncope / Q000209:etiology* / Q000401:mortality; D013610:Tachycardia / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology