What is the yield of screening echocardiography in pediatric syncope?

OBJECTIVE: To determine the yield of screening echocardiography in the evaluation of pediatric syncope.
DESIGN: All patients diagnosed with syncope from January 1993 to January 1999 were identified and their records were reviewed for age, weight, sex, year of presentation, personal and family history, physical examination, and cardiac diagnostic testing. Cardiac defects were identified by reviewing echocardiograms and reports.
RESULTS: The 480 patients (268 females) ranged in age from 1.5 to 18.0 years old and ranged in weight from 10.3 to 113.6 kg. Final diagnoses included noncardiac causes in 458, long QT syndrome in 14, arrhythmias in 6, and cardiomyopathy in 2. An abnormal history, physical examination, or electrocardiogram identified 21 of the 22 patients with a cardiac cause of syncope. Of the 322 (67%) echocardiograms performed, abnormalities were detected in 37. These abnormalities included 26 minor valve anomalies, 7 hemodynamically insignificant shunt lesions, 2 mildly decreased left ventricular shortening fractions, and 2 cardiomyopathies. Only the 2 cardiomyopathies were considered to be potential causes of syncope, and in both cases, the electrocardiogram was markedly abnormal. A similar percentage of echocardiograms were ordered during the first and last 3 years of the study (61% vs 71%).
CONCLUSION: History, physical examination, and electrocardiography provide a screening protocol that allows the identification of a cardiac cause of syncope in the overwhelming majority of pediatric patients. In the absence of a positive screen result, the echocardiogram does not contribute to the evaluation of syncope in children. We speculate that primary care providers and pediatric cardiologists continue to use echocardiography because of the paucity of data regarding its value in pediatric syncope. However, this study shows little benefit of screening echocardiography and should discourage its routine use.