Accuracy of Interpretation of Preparticipation Screening Electrocardiograms.
Hill AC, Miyake CY, Grady S, Dublin AM. Journal of Pediatrics. 2011; July 9. [Epub ahead of print]
Universal use of screening electrocardiograms (ECGs) during preparticipation physical exams (PPE) is one of the most controversial topics in sports medicine. The American Heart Association has not recommended implementation of screening ECGs for young athletes but there is a lack of consensus on this issue. Some physicians are in favor of including ECGs as part of the standard PPE based on recommendations by the International Olympic Committee (IOC) and European Society of Cardiology—both of whom endorse universal screening with ECG as part of the PPE. The purpose of this study was to assess a previously uninvestigated aspect of this controversy, which is the accuracy with which these preparticipation ECGs are interpreted by pediatric cardiologists. The authors administered an online questionnaire asking for interpretations of 8 normal and 10 abnormal ECGs as well as soliciting recommendations for further testing and treatment. Two pediatric electrophysiologists who completed the online questionnaire and interpreted the ECGs with 100% concordance represented the gold standard “correct” responses. Among 53 respondents that completed the survey (25% of cardiologists invited to participate), the average number of correct ECG interpretations was 12.4 out of 18 ECGs (69% correct, range = 34% to 98%). The 53 pediatric cardiologists had a sensitivity of 68% (sensitivity: positively diagnose a patient who has pathology) and specificity of 70% (specificity: not falsely diagnosing a healthy patient) for the recognition of any abnormality. In other words, the false-negative and false-positive rates were 32% and 30%, respectively. Sports participation was correctly permitted in 74% of cases and correctly restricted in 81% of cases. Participating pediatric cardiologists gave correct sports participation guidance most commonly in cases of long QT syndrome and myocarditis; however, proper guidance was least commonly provided in cases of hypertrophic cardiomyopathy, Wolff-Parkinson-White syndrome, and pulmonary hypertension.
This study is important because it shows that ECGs interpreted by pediatric cardiologists do not achieve the sensitivity or specificity needed to function as an effective universal screening test for diseases that increase the risk of sudden cardiac death. These findings are particularly concerning given the possibility that almost half of the respondents who began the survey did not finish, and these results were not included in the data interpretation. If pediatric cardiologists chose not to finish the survey because they were unsure of the correct responses, then the reported accuracy among those who did finish would look better than all of the cardiologists that started the survey. The diseases that underlie sudden cardiac death are difficult to identify from ECG findings – even in the hands of the experts expected to interpret them. This study suggests that if ECGs are universally employed to screen young athletes, it could lead to high rates of inappropriate inclusion and exclusion from sports with significant sequelae. Other authors, most notably Harmon et al have recommended that ECGs may be reasonable as a screening test in high-risk populations where the incidence of underlying heart disease is increased (see SMR post on Harmon et al). However, this paper suggests that even if abnormalities are more likely to be present (i.e. in high-risk populations), cardiologists are not always finding or addressing them which is a serious concern for using ECGs at all – unless there is more specific training required for the specialists who are reading them.
Written by: Hallie Labrador, Marc Harwood
Reviewed by: Jeffrey Driban