University of Michigan
Department of Pediatrics
Evidence-Based Pediatrics Web Site

Question

• In pediatric patients presenting with syncope, what is the additional benefit of echocardiography in conjunction with history, physical exam and electrocardiogram findings to screen for a cardiac cause?

Clinical Bottom Lines

1. Although a history and physical examination alone are not sufficient to identify all patients with a cardiac cause of syncope, a screening protocol, including a thorough history, physical examination and ECG will allow the identification of cardiac syncope with a sensitivity of 96%.
2. In the absence of a history of exercise-induced syncope, positive family history, abnormal physical exam, and/or abnormal ECG, the echocardiogram does not contribute to the evaluation of pediatric syncope.
   

Summary of Key Evidence

1. In the present study, 458 of 480 total patients (95%) had a final diagnosis of noncardiac syncope and 22 (4.6%) were diagnosed with a cardiac etiology.¹
2. 322 patients underwent an echocardiogram and 37 (12%) had an abnormality identified. Of these, 4 patients were ultimately diagnosed with cardiac syncope. The other 18 patients with cardiac syncope had normal echocardiograms. The sensitivity of the echo to diagnose a cardiac etiology of syncope was calculated to be 18% and the specificity 93%. This results in a LR(+) of 2.57 and a LR(-) of 0.88, neither of which are particularly helpful.
3. Of the 22 patients diagnosed with cardiac syncope, 21 had an abnormal screening protocol (H&P plus ECG). The 1 remaining patient was found by 24-hour holter monitoring and had a normal echocardiogram. The sensitivity of the screening protocol was calculated to be 96% and the specificity 36%. This results in a more useful LR(-) of 0.11. The result from a positive test is still not very helpful (LR(+)=1.50).
   

Additional Comments

• This was a cross-sectional study, which consisted of a retrospective review of patients in a pediatric cardiology clinic database with a diagnosis of syncope.
• There was no "gold standard" to diagnose syncope with which to compare either the echo or the screening protocol.
  

Citation

1. Ritter S, Tani LY, Etheridge SP, Williams RV, Craig JE, Minich LL. What is the yield of screening echocardiography in pediatric syncope? Pediatrics 2000;105(5):E58.

CAT Author: Wahida Abaza, MD

CAT Appraisers: Alex Kemper, MD

Date appraised: October, 8, 2003