What is the interpretation of ST elevation in lead aVR (augmented voltage right) in a patient with suspected acute coronary syndrome and poor R wave progression in leads V3-V6?

ST Elevation in Lead aVR: Interpretation

ST elevation in lead aVR, particularly when accompanied by widespread ST depression in other leads, strongly suggests severe left main coronary artery disease or proximal left anterior descending artery occlusion and represents a high-risk acute coronary syndrome requiring emergent cardiac catheterization. 1, 2

Primary Clinical Significance

ST elevation in aVR occurs when the ST-segment spatial vector is directed superiorly and to the right, which happens in specific high-risk coronary occlusions 3:

• Left main coronary artery (LMCA) obstruction is the most critical diagnosis associated with ST elevation in aVR, particularly when combined with diffuse ST depression in multiple leads 1, 2
• Proximal LAD occlusion above the first septal and diagonal branches produces ST elevation in aVR along with V1-V4, I, and aVL, with reciprocal ST depression in inferior leads II, III, and aVF 3, 4
• The combination of ST elevation in aVR with multilead ST depression carries high mortality risk and may represent a STEMI equivalent 1

Pattern Recognition Algorithm

When you see ST elevation in aVR, systematically evaluate:

Step 1: Quantify the ST elevation

• Measure ST elevation at the J-point in aVR 3
• Compare the magnitude of ST elevation in aVR to V1 (aVR ≥ V1 suggests LMCA disease) 5

Step 2: Assess for diffuse ST depression

• Look for ST depression in 6 or more leads, particularly precordial and lateral leads 1
• This pattern of "diffuse ST depression + aVR elevation" is the classic "aVR sign" indicating severe multivessel or left main disease 1

Step 3: Evaluate other high-risk features

• ST elevation greater in aVL than aVR suggests proximal LAD rather than left main 3
• ST depression greater in lead III than lead II points toward proximal LAD 3
• Presence of ST elevation in V1 alongside aVR further supports proximal LAD occlusion 3, 4

Context of Poor R Wave Progression in V3-V6

Poor R wave progression in leads V3-V6 combined with ST elevation in aVR suggests:

• Anterior wall involvement from proximal LAD occlusion, as the basal portion of the left ventricle and interventricular septum are affected 3
• Previous anterior myocardial infarction with significant Q waves, which would indicate chronic coronary disease now presenting acutely 3
• The poor R wave progression may represent either acute injury or old infarction—comparison with prior ECGs is essential 3

Critical Management Implications

Immediate actions required:

• Activate the cardiac catheterization laboratory emergently—these patients require urgent revascularization 1, 2, 6
• Expect hemodynamic instability, increased risk of cardiogenic shock, and higher in-hospital mortality 6
• These patients have larger infarction areas and greater likelihood of acute heart failure at presentation 6
• Early revascularization is mandatory as mortality increases from baseline to 25-30% with left main involvement 7

Important Caveats

Not all ST elevation in aVR indicates left main disease:

• Diffuse LMCA vasospasm without fixed stenosis can produce identical ECG findings 8
• Multiple other high-risk conditions beyond left main disease can cause the aVR sign 1
• The specificity for left main disease has been questioned, though the finding always indicates high-risk pathology 1

Clinical context matters:

• The ECG should ideally be obtained during symptoms and compared with tracings when symptoms resolve 3
• A completely normal ECG during chest pain should redirect attention to non-ischemic causes 3
• ST-segment shift and T-wave changes are the most reliable ECG indicators of unstable coronary disease 3

Bottom Line

ST elevation in aVR is never benign in the setting of suspected acute coronary syndrome. It signals either severe left main disease, proximal LAD occlusion, or diffuse multivessel disease—all requiring immediate invasive management. The combination with poor R wave progression in anterior leads suggests extensive anterior wall involvement, further elevating risk. Do not delay cardiac catheterization in these patients. 1, 2, 6