RESUMO
OBJECTIVES: Despite the low diagnostic yield of echocardiogra0, it is often used in the evaluation of syncope. This study determined whether patients without abnormalities in the initial evaluation benefit from transthoracic echocardiogram (TTE) and the clinical factors predicting an abnormal TTE. METHODS: This study enrolled 241 patients presenting to the emergency department with syncope. The TTE results were analyzed based on risk factors suggesting cardiogenic syncope in the initial evaluation. RESULTS: Of the 115 patients with at least one risk factor, 97 underwent TTE and 27 (27.8%) had TTE abnormalities. In comparison, of the 126 patients without risk factors, 47 underwent TTE and only 1 (2.1%) had TTE abnormalities. Significantly different factors between patients with normal and abnormal TTE findings were entered in a multiple logistic regression analysis, which yielded age [adjusted odds ratio (aOR), 1.09; 95% CI, 1.02-1.15; p=0.006], an abnormal electrocardiogram (ECG) (aOR, 7.44; 95% CI, 1.77-31.26; p=0.010), and a brain natriuretic peptide (BNP) level of >100pg/mL (aOR, 2.64; 95% CI, 1.21-5.73; p=0.011) as independent predictors of TTE abnormalities. The cutoff value of age predicting an abnormal TTE was 59.0years (area under the curve, 0.777; p<0.001). CONCLUSION: A patient who is older than 59years or has an abnormal ECG or an elevated BNP level may benefit from TTE. Otherwise, TTE should be deferred in patients with no risk factors in the initial evaluation.