Accurate automatic detection of electrode interchange in the electrocardiogram

In recording an electrocardiogram (ECG), an interchange of electrodes may e asily go unnoticed. Automatic detection would be desirable, but current alg orithms, when dealing with more than left arm-right arm reversal, have mode rate sensitivity. We propose a novel approach that uses the redundancy of i nformation in the standard 12-lead ECG. We assume that each of the 8 indepe ndent electrocardiographic leads can be reconstructed from the 7 others in reasonable approximation. The correlation between any electrocardiographic lead and its reconstruction should be higher if the electrodes are correctl y placed than when some interchange were present. The difference in correla tion should have discriminative power. This was verified on a set of 3,305 ECGs for 14 common electrode interchange errors. The material was split in a learning and test set, and general reconstruction coefficients were compu ted from the learning set. For each interchange, electrode-error ECGs were derived by rearranging leads of the unaltered ECGs. Correlations between th e actual leads and their reconstructions were computed for all ECGs. From t he differences in lead correlation, decision rules were derived for each ki nd of interchange. All 14 rules had specificities of greater than or equal to 99.5% in the test set. Sensitivities were greater than or equal to 93% f or 11 rules, and left arm-left leg electrode reversal scored low. (C) 2001 by Excerpta Medica, Inc.