Errors in the Computerized Electrocardiogram Interpretation of Cardiac Rhythm

Background: More than 100 million computer-interpreted electrocardiograms (ECG-C) are obtained annually. However, there are few contemporary published data on the accuracy of cardiac rhythm interpretation by this method.

Purpose: The purpose of this study is to determine the accuracy of ECG-C rhythm interpretation in a typical patient population.

Methods: We compared the ECG-C rhythm interpretation to that of 2 expert overreaders in 2112 randomly selected standard 12-lead ECGs.

Results: The ECG-C correctly interpreted the rhythm in 1858 and incorrectly identified the rhythm in 254 (overall accuracy, 88.0%). Sinus rhythm was correctly interpreted in 95.0% of the ECGs (1666/1753) with this rhythm, whereas nonsinus rhythms were correctly interpreted with an accuracy of only 53.5% (192/359) (P < .0001). The ECG-C interpreted sinus rhythm with a sensitivity of 95% (confidence interval, 93.8-96.7), specificity of 66.3%, and positive predictive value of 93.2%. The ECG-C interpreted nonsinus rhythms with a sensitivity of 72%, (confidence interval, 68.7-73.7), a specificity of 93%, and a positive predictive value of 59.3%. Of the 254 ECGs that had incorrect rhythm interpretation, additional major errors were noted in 137 (54%).

Conclusions: The ECG-C demonstrates frequent errors in the interpretation of nonsinus rhythms. In addition, incorrect rhythm interpretation by the ECG-C was frequently further compounded by additional major inaccuracies. Expert overreading of the ECG remains important in clinical settings with a high percentage of nonsinus rhythms.