Bad cable, good cable

Abstract

A 23-year-old female with history of smoking but otherwise no significant medical history presented with recurrent episodes of chest pain. An electrocardiogram (EKG) was performed, which showed T-wave inversion in leads V1 and V3 but not V2. There was also an abnormal Rwave progression with an abnormally prominent R wave in lead V2 (Fig. 1), raising the suspicion of leads V2 and V3 reversal. Switching cables did not fix the problem. Because this was suspected to be most likely artifactual, a different EKG machine was used with a more reasonable R-wave progression (Fig. 2). Upon inspection by a biomedical consultant, the cable on the first machine was found to be malfunctioning, with lead (V2) shorting with the ground and was subsequently replaced. It was thought that, with frequent use of the EKG machine, not uncommon practice in a cardiology office, the actual current generated, although