Are echocardiography, telemetry, ambulatory electrocardiography monitoring, and cardiac enzymes in emergency department patients presenting with syncope useful tests? A preliminary investigation

Abstract

Background: Prior studies of admitted geriatric syncope patients suggest that diagnostic tests affect management < 5% of the time; whether this is true among all emergency department (ED) patients with syncope remains unclear.

Objectives: To determine the diagnostic yield of routine testing in the hospital or after ED discharge among patients presenting to an ED with syncope.

Methods: A prospective, observational, cohort study of consecutive ED patients aged ≥ 18 years presenting with syncope was conducted. The four most commonly utilized tests (echocardiography, telemetry, ambulatory electrocardiography monitoring, and troponin) were studied. Interobserver agreement as to whether test results determined the etiology of the syncope was measured using kappa (κ) values.

Results: Of 570 patients with syncope, 73 patients (8%; 95% confidence interval 7-10%) had studies that were diagnostic. One hundred fifty (26%) had echocardiography, with 33 (22%) demonstrating a likely etiology of the syncopal event, such as critical valvular disease or significantly depressed left ventricular function (κ = 0.75). On hospitalization, 330 (58%) patients were placed on telemetry, and 19 (3%) had worrisome dysrhythmias (κ = 0.66). There were 317 (55%) patients who had troponin levels drawn, of whom 19 (3%) had positive results (κ = 1); 56 (10%) patients were discharged with monitoring, with significant findings in only 2 (0.4%) patients (κ = 0.65).

Conclusion: Although routine testing is prevalent in ED patients with syncope, the diagnostic yield is relatively low. Nevertheless, some testing, particularly echocardiography, may yield critical findings. Current efforts to reduce the cost of medical care by eliminating nondiagnostic medical testing and increasing emphasis on practicing evidence-based medicine argue for more discriminate testing when evaluating syncope.

Keywords: ECG; echocardiography; emergency; syncope; telemetry; tests.