An unusual ECG artifact? Re: ST elevation in one lead

Background: We describe an unusual finding in an electrocardiogram showing ST‐segment elevation not related to coronary artery stenosis, pericarditis, bundle branch block, or other well known disorders. Case Presentation: A 60‐year‐old African American woman admitted for elective coronary artery bypass graft surgery. A temporary pacemaker with pacing wires was placed intraoperatively for prevention and treatment of postoperative bradyarrhythmia. One day following uneventful surgery, her electrocardiogram demonstrated marked ST segment elevation confined to lead V(6). These changes were comparable to tracings obtained from direct epicardial electrocardiogram, due to contact between the V(6) electrode and the temporary pacemaker ventricular lead wire. Conclusion: Current‐of‐injury patterns are represented on surface electrocardiogram by deviations of the ST segment from the isoelectric baseline. The pacing wire causes direct localized epicardial current‐of‐injury, affecting the action potential and the resting membrane potentials of cardiomyocytes. Our case report demonstrates epicardial current‐of‐injury pattern obtained via surface rather than epicardial electrocardiogram, with surface leads as surrogates of epicardial tracing. Measurement of ST‐segment shifts from the epicardial electrocardiogram has been shown to provide a more sensitive measurement of ischemia when compared to surface precordial ECG.