ABSTRACT
BACKGROUND: A fraction of routine resting ECG's are taken with electrode positions interchanged, leading to possible clinical misinterpretation. OBJECTIVE: Develop and test a method to detect and prevent electrode reversals at the electrocardiograph before the ECG is acquired. METHOD: The algorithm is based on QRS axis and P amplitudes for limb electrode reversals, and P-Q-RS amplitude distances to detect chest electrode reversals. The evaluation method involved a large (>18,000) hospital database for which serial ECG's were available and was based on simulated juxtapositions. RESULTS: The 7 most common lead reversals could be detected with a specificity of 99.8% per type and an average sensitivity of 90%, excluding LA-LL reversal (22% sensitivity). DISCUSSION: Results are similar to retrospective studies that used smaller, more homogeneous datasets. CONCLUSION: The early warning system reduces the ECG's recorded with reversal by 80%, at the price of a modest false alert rate of 1.4%.
