Analysis of emergency department interpretation of electrocardiograms

The objective of the study was to determine the concordance of emergency physicians' and cardiologists' interpretations of emergency department (ED) electrocardiograms (ECG), to evaluate the impact of ECG misinterpretation on patient management, and to determine error rates as a function of the level of physician training and the specific ECG diagnoses. ECG interpretations were registered prospectively using a programmed-response data sheet. A second blinded interpretation by a staff cardiologist was assumed to be correct. Only ECG discrepancies with potential or probable clinical importance were considered as errors. The ED management of patients with ECG misinterpretations was reviewed by the investigators. The study was performed at an urban university hospital using 300 consecutive ED ECGs. The analysis found 154 errors of interpretation of which nine had probable clinical significance, and 56 had indeterminant significance. The concordance was weak at 0.69 (Kappa = 0.32, weighted Kappa = 0.30) with a significant discordance (McNemar Chi 2:P < 0.05). Error rates did not differ significantly between the diverse categories of physicians. In two cases, interpretation errors impacted patient management decisions but not patient outcomes. The most frequent errors involved repolarization abnormalities, ventricular hypertrophy and hemi-blocks. While discordance was significant, errors in ECG interpretation rarely impacted patient management. Prospective evaluation of ECG interpretation may be a useful means of gauging physician skills. It can also serve to focus educational activities on problem areas in electrocardiography.