Reversal of Fortune: ECG STEMI Mimic

Abstract

This column discusses what appears to be a lead reversal in a 12-lead electrocardiogram (ECG) of a routine low-risk chest pain evaluation in a 36-year-old man. A 12-lead ECG was completed and identified ST changes suggestive of ischemia in the inferior leads. Findings in the ECG suggested arm lead reversal that created an ST-segment elevation myocardial infarction (STEMI) mimic. Repeating the ECG and correcting the arm lead mistake identified a correction of these changes and identified an ECG more suggestive of benign early repolarization or J-point elevation. This case discusses the importance of identifying ECG findings that may suggest arm lead reversal and how sometimes misplaced leads could create the appearance of an STEMI. This is a review of the case, key points to interpreting ECGs for possible lead reversal and identifying the REVERSE mnemonic. Key words: arm lead reversal, early repolarization, ECG lead misplacement, J-point elevation, 12-lead ECG, low-risk chest pain, STEMI mimic, vector changes E MERGENCY MEDICINE is an art form, as well as a science. It requires the clinician to understand the abnormal while having a clear understanding of what is "normal." We are often specialists at being generalists in emergency medicine requiring clinicians to have broad knowledge base of a variety of topics. Where the art form becomes apparent is when a clinician is trying to interpret the utility of data. A white blood cell count of 14, a temperature of 100.1°F, a pulse oximetry of 90%-these marginal

Incorrect Electrocardiogram Lead Placement in ST-Segment–Elevation Myocardial Infarction

“…Limb-lead reversals are difficult to recognize and can lead to misdiagnoses. False STEMIs due to limb-lead reversal have also been reported . Among patients with STEMI, limb-lead reversal may cause confusion and delay in identifying the culprit vessel, as demonstrated in the present case.…”

“…False STEMIs due to limb-lead reversal have also been reported. 3 Among patients with STEMI, limb-lead reversal may cause confusion and delay in identifying the culprit vessel, as demonstrated in the present case. Promptly identifying lead misplacement and repeating the ECG with correct lead placement is critical for the accurate diagnosis and management of any clinical situation.…”

Myocardial Infarction Simulated From Improper Telemetry (MISFIT): An Autobiographical Case Report

“…M: mnemonic; mV: millivolt; <: less than Technological advances in the instruments used for performing this task have begun to incorporate algorithms that enable machine learning techniques for detecting electrode misplacement and interchanges when recording electrocardiograms [19,20]. Once the diagnosis of inadequate placement of the electrocardiogram electrodes is suspected, particularly when the patient's clinical findings are not suggestive of ischemic heart disease, the electrocardiogram should be repeated after confirming that all the leads have been correctly placed [1,4,6].…”

“…A non-intentional error caused by the improper placement of one or more recording electrodes on the skin can result in an inaccurate evaluation of the individual being assessed. For example, misplacement of the leads can mimic a myocardial infarction [1,[4][5][6][7][8][9].…”

“…The initial approach to the management of a MISFIT is to consider the possibility of lead misplacement [1,3,5,8]. "REVERSE" is a mnemonic that may help to identify lead reversal on a 12-lead electrocardiogram (Table 5) [4]. b Also negative R wave in lead I, positive R wave in aVF.…”