Epidemiology of syncope in hospitalized patients

OBJECTIVE: To describe the etiologies of syncope in hospitalized patients a nd determine the factors that influence survival after discharge. DESIGN: Observational retrospective cohort, SETTING: Department of Veterans Affairs hospital, group-model HMO, and Medi care population in Oregon. PATIENTS: Hospitalized individuals (n = 1,516: m ean age +/- SD, 73.0 +/- 13.4 years) with an admission or discharge diagnos is of syncope (ICD-9-CM 780.2) during 1992, 1993, or 1994, MEASUREMENTS AND MAIN RESULTS: During a median hospital stay of 3 days, mos t individuals received an electrocardiogram (97%) and prolonged electrocard iographic monitoring (90%), but few underwent electrophysiology testing (2% ) or tilt-table testing (0.7%). The treating clinicians identified cardiova scular causes of syncope in 19% of individuals and noncardiovascular causes in 40%. The remaining 42% of individuals were discharged with unexplained syncope. Complete heart block (2.4%) and ventricular tachycardia (2.3%) wer e rarely identified as the cause of syncope. Pacemakers were implanted in 2 8% of the patients with cardiovascular syncope and 0.4% of the others. No p atient received an implantable defibrillator. Ah-cause mortality +/- SE was 1.1% +/- 0.3% during the admission, 13% +/- 1% at 1 year, and 41% +/- 2% a t 4 years. The adjusted relative risk (RR) of dying for individuals with ca rdiovascular syncope (RR 1.18; 95% confidence interval [CI] 0.92, 1.50) did not differ from that for unexplained syncope (RR 1.0) and noncardiovascula r syncope (RR 0.94; 95% CI 0.77, 1.16), CONCLUSIONS: Among these elderly patients hospitalized with syncope, noncar diovascular causes were twice as common as cardiovascular causes. Because s urvival was not related to the cause of syncope, clinicians cannot be reass ured that hospitalized elderly patients with noncardiovascular and unexplai ned syncope will have excellent outcomes.