ST Elevation in Lead aVR: Clinical Significance
ST elevation in lead aVR, particularly when accompanied by widespread ST depression in other leads, most commonly indicates severe left main coronary artery disease or multivessel coronary disease and mandates urgent cardiac catheterization. 1
Primary Diagnostic Significance
Left Main or Multivessel Disease (Most Common)
- ST elevation ≥0.5 mm in aVR combined with ST depression in ≥8 surface leads strongly predicts left main or three-vessel disease, especially when accompanied by hemodynamic compromise 1, 2
- The pattern of ST elevation in aVR that is greater than or equal to ST elevation in V1 distinguishes left main disease from proximal LAD occlusion with 81% sensitivity and 80% specificity 2
- Patients with ST elevation in aVR plus elevated troponin have the highest rates of left main or three-vessel disease (62%) and 90-day adverse outcomes (47%) 3
Proximal LAD Occlusion
- Proximal LAD occlusion above the first septal and diagonal branches produces ST elevation in aVR along with ST elevation in V1-V4, I, and aVL, with reciprocal ST depression in inferior leads 1, 4
- This differs from left main disease by having more prominent ST elevation in V1 compared to aVR 2
Critical Management Algorithm
Immediate Actions (Within Minutes)
- Activate cardiac catheterization laboratory immediately if patient has ongoing chest pain, hemodynamic instability (hypotension, cardiogenic shock), or ST elevation in aVR with widespread ST depression 1
- Initiate continuous ECG monitoring for life-threatening arrhythmias 5
Urgent Evaluation (Within Hours)
- Perform echocardiography to assess wall motion abnormalities, left ventricular function, and mechanical complications 1
- Obtain serial troponin measurements—the combination of ST elevation in aVR with elevated troponin independently predicts death or MI (OR 13.8) 3
- Proceed to urgent catheterization within hours even if hemodynamically stable when severe coronary disease pattern is present 1
Important Differential Diagnoses
Non-Coronary Causes to Consider
- Takotsubo syndrome typically does NOT show ST elevation in aVR (this is a key distinguishing feature), though it may show ST elevation in other leads 5
- Severe anemia with demand ischemia can produce ST elevation in aVR with diffuse ST depression 6
- Drug-induced vasospasm and tachycardia may mimic this pattern 6
- Diffuse left main coronary vasospasm without fixed stenosis (rare) 7
ECG Pattern Recognition
- The De Winter pattern (0.5-1 mm ST elevation in aVR with upsloping ST depression in precordial leads) indicates proximal LAD occlusion requiring emergent catheterization 1
- ST elevation in aVR occurs in 88% of acute left main occlusions versus only 43% of LAD occlusions 2
Prognostic Implications
Risk Stratification
- ST elevation in aVR is an independent predictor of left main/three-vessel disease (OR 2.05) even after adjusting for other ECG findings 8
- Higher magnitude of ST elevation in aVR correlates with increased mortality in left main disease 2
- ST elevation in aVR independently predicts death, MI, or urgent revascularization at 90 days (OR 12.8) 3
Critical Pitfalls to Avoid
- Do not delay catheterization to obtain stress imaging when ST elevation in aVR is present with widespread ST depression—this pattern indicates severe disease requiring invasive evaluation 1
- Do not assume Takotsubo syndrome if ST elevation in aVR is present; this finding argues against Takotsubo and favors obstructive coronary disease 5
- Do not rely on nitroglycerin response for diagnosis—complete normalization of ST changes after nitroglycerin suggests vasospasm but still requires early angiography within 24 hours 5
- Remember that lead aVR views the heart from the right shoulder and represents a global ischemia pattern when elevated, not a specific anatomic territory 5