RECOGNITION OF ELECTROCARDIOGRAPHIC ELECTRODE MISPLACEMENTS INVOLVING THE GROUND (RIGHT LEG) ELECTRODE

Accurate electrocardiographic (ECG) interpretation by computer or manually requires that the electrocardiogram be recorded with all electrodes in proper positions. All possible electrode placement errors involving the active limb electrodes (right and left arm, and left leg) have been described.1 The most frequent electrode placement error is the left/right arm electrode reversal; because it is so common and easily recognized, many computerized ECG recorders have built-in logic to recognize it.2,3 The ground electrode, placed on the right leg by convention, may be positioned anywhere on the body without affecting the ECG waveforms. However, if it is erroneously positioned on an arm and if an arm electrode is therefore positioned on the right leg, a characteristic alteration of the electrocardiogram occurs. There are no strategies in computerized ECG recorders for automatic recognition of this electrode reversal, and it is not discussed in standard textbooks of electrocardiography. 1,4,5 The main purposes of this study were to: (1) describe the characteristic ECG appearance of a right arm/leg electrode reversal, (2) propose an algorithm for its automated recognition, and (3) survey cardiologists' recognition of this electrode reversal. © 1993.