Accuracy Of The Limb-lead Electrocardiogram In Identifying Conditions Associated With Sudden Cardiac Death

Abstract

The best screening strategy to prevent sudden cardiac death (SCD) in athletes remains unknown. Using the electrocardiogram (ECG) as a part of a pre-participation examination remains controversial due to the cost and rate of false positives. Screening athletes can be both time intensive and costly. Our previous study demonstrated that using a limb-lead ECG is faster than using a 12-lead ECG. However, the utility and accuracy of limb-leads alone in identifying cardiac abnormalities associated with SCD have never been studied. PURPOSE: To assess agreement and diagnostic accuracy in the interpretation of limb lead v. 12-lead ECG in identifying cardiac abnormalities associated with SCD. METHODS: This study compared the interpretation accuracy of 4 physicians evaluating publicly available ECGs of the most common cardiac conditions associated with SCD in athletes. 4 Medical Sports Medicine fellows participated in the study and each interpreted a total of 100 ECGs: 50 normal ECGs (25 limb lead and 25 12-lead) and 50 abnormal ECGs (25 limb lead and 25 12-lead). The agreement between limb lead and 12-lead ECGs was assessed by Cohen’s kappa coefficient and the accuracy of identifying an abnormal ECG was compared across limb lead and 12-lead ECGs using a chi-squared test. Inter-rater and intra-rater reliability were assessed by estimating the Fleiss’s kappa coefficient. RESULTS: Preliminary data of 150 interpreted ECGs showed an accuracy of 77.8% and 82.1% in identifying abnormal from normal ECGs using 12-lead v. limb-lead, respectively (p = 0.513). Based on the readings of the physicians in this study, the sensitivity of limb-lead was 97.2% and 12-lead was 89.5%. The specificity of limb-lead was 69.1% and 12-lead was 64.7%. CONCLUSIONS: There was no significant difference in the accuracy of physicians’ interpretations of limb lead ECGs compare to standard 12-lead ECGs in identifying cardiac conditions associated with SCD.