ST segment elevation in one lead: A case report

Abstract

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. © 2012, Wiley Periodicals, Inc.