The Role of 18-Lead ECG in Inferior and Posterior Wall Myocardial Infarction: A Review

Abstract

Background: Inferior Wall Myocardial Infarction (IWMI) is often associated with Posterior Wall Myocardial Infarction (PWMI), which may be overlooked in a standard 12-lead electrocardiogram (ECG). An 18-lead ECG, which includes additional right-sided and posterior leads, improves diagnostic accuracy and facilitates early intervention. Objective: This review aims to evaluate the role of the 18-lead ECG in the detection and management of IWMI with PWMI, emphasizing its diagnostic advantages, limitations of the 12-lead ECG, and its impact on clinical decision-making. Methods: A systematic review of literature from databases including PubMed, Scopus, and Web of Science was conducted. Studies focusing on the diagnostic accuracy, prognostic value, and clinical outcomes of 18-lead ECG in acute myocardial infarction were included. Results: IWMI is characterized by ST-segment elevation in leads II, III, and aVF, with reciprocal depression in aVL. PWMI is often suggested by ST depression in V1–V3, tall R waves, and upright T waves, which can be misinterpreted as anterior ischemia. The addition of posterior leads (V7–V9) confirms ST elevation in PWMI, while right-sided leads (V3R–V5R) help diagnose right ventricular infarction (RVI). Studies demonstrate that using an 18-lead ECG significantly improves detection rates, leading to more timely reperfusion therapy and better patient outcomes. Conclusion: The 18-lead ECG is a valuable diagnostic tool that enhances the identification of posterior and right ventricular infarctions in IWMI patients. Its routine use can improve clinical decision-making and reduce misdiagnosis-related complications. Further large-scale studies are necessary to standardize its use in emergency and cardiology practice.

Keywords: Inferior Myocardial Infarction, Posterior Myocardial Infarction, 18-lead ECG, Right Ventricular Infarction, ST-segment Elevation, Electrocardiography