High-Risk Electrocardiographic Patterns in Acute Myocardial Infarction: Early Recognition, Clinical Implications, and Therapeutic Decision-Making

Background: The 12-lead electrocardiogram (ECG) remains the cornerstone of rapid diagnosis in acute myocardial infarction (AMI). Early identification of high-risk ECG patterns is critical for timely intervention, risk stratification, and improving clinical outcomes. Objective: This article reviews the electrocardiographic hallmarks of AMI, emphasizing high-risk features that necessitate emergent reperfusion therapy, discriminate STEMI from NSTEMI, and predict adverse cardiovascular events. Methods: A narrative review of current literature was conducted, focusing on ECG patterns associated with acute coronary syndromes (ACS), including ST-segment elevation (STE), ST depression, hyperacute T waves, Q waves, and conduction abnormalities. Special attention was given to STEMI-equivalent patterns and occlusive myocardial ischemia. Results: Key high-risk ECG findings include: STE in ≥2 contiguous leads (indicating transmural ischemia). New left bundle branch block (LBBB) meeting Sgarbossa criteria. Global ST depression with STE in aVR (suggesting left main or triple-vessel disease). Posterior STEMI (ST depression in V1–V3 with dominant R waves). De Winter’s T waves (upwardly concave ST depression with hyperacute T waves in precordial leads). These patterns correlate with large ischemic burden, proximal coronary occlusion, and higher mortality. Conclusion: Mastery of high-risk ECG patterns enables rapid triage, appropriate revascularization, and reduced morbidity in AMI. Future advancements in AI-assisted ECG interpretation may further enhance early detection.