GENERAL CLINICAL INVESTIGATION/ORIGINAL CONTRIBUTION Risk Stratification of Patients With Syncope

Methods: Two prospective studies were carried out at a large urban teaching hospital ED. One cohort of 252 patients with syncope who reported to the ED was used to develop the risk classification system; a second cohort of 374 patients with syncope was used to validate the system. Data from the patient's history, physical examination, and ED ECG were used to identify predictors of arrhythmias or mortality within the first year. Arrhythmias were detected by cardiac monitoring or electrophysiologic studies. Logistic regression and Cox proportional hazards models were used to identify the important risk factors for the classification system. Performance of the system was measured by comparing the proportion of patients with arrhythmias or death at various levels of the risk and receiver operating characteristic curves.