ST elevation in lead aVR – a marker of critical left main coronary artery stenosis

Rationale: Lead augmented vector right (aVR) has historically been overlooked in acute coronary syndromes. ST-segment elevation (STE) in lead aVR with diffuse ST depression in multiple leads has emerged as a critical marker for left main coronary artery (LMCA) stenosis and triple-vessel disease (3VD). Recognition of this high-risk electrocardiogram (ECG) pattern is essential for timely diagnosis and improved outcomes. Patient concerns: In this retrospective case series, 5 consecutive patients presented to the emergency department between January 2023 and June 2024 with acute chest pain or cardiac arrest. Diagnoses: All 5 patients exhibited ECG findings of STE in aVR (≥1 mm) with diffuse ST depressions (≥1 mm) in ≥6 leads. All underwent coronary angiography within 24 hours, which confirmed LMCA stenosis (70%–99%; mean STE in aVR: 3.0 mm). A narrative literature review was performed using PubMed/MEDLINE databases (2000–2024) with search terms including “lead aVR,” “ST-segment elevation,” “left main coronary artery,” and “acute coronary syndrome.” Literature review shows that STE ≥0.5 mm in aVR with diffuse ST depression has been reported to have a sensitivity of 78% and specificity of 86% for LMCA/triple-vessel disease in prior studies. However, it is important to recognize that this ECG pattern can occur in other conditions, including severe anemia, shock states, and aortic dissection. STE ≥1 mm increases diagnostic yield. Patients with this pattern have higher in-hospital mortality (8.6%–19.4% vs 1.3%) and increased heart failure and reinfarction. Interventions: A total of 2 patients underwent coronary artery bypass grafting, 2 underwent percutaneous coronary intervention, and 1 was managed medically. Outcomes: No in-hospital deaths occurred. Lessons: STE in aVR with diffuse ST depression represents a high-risk ECG pattern that should prompt urgent invasive evaluation. Recognition of this high-risk ECG pattern is essential for timely diagnosis of critical LMCA stenosis and improved outcomes. However, findings from this small case series require validation in larger prospective cohorts.