What is the clinical significance of an electrocardiogram (ECG) showing poor R wave progression, inverted T waves in leads aVR (augmented vector right), II, and III, and an elevated QTc (corrected QT) interval?

ECG with Poor R Wave Progression, T Wave Inversions in aVR/II/III, and Prolonged QTc

Most Likely Diagnosis

This ECG pattern most likely represents either acute myocardial ischemia involving the left anterior descending (LAD) coronary artery or an underlying cardiomyopathy, particularly arrhythmogenic cardiomyopathy with inferior wall involvement. 1, 2, 3

Critical Immediate Considerations

High-Risk Features Requiring Urgent Evaluation

• Poor R wave progression combined with T wave inversions constitutes a high-risk ECG pattern that demands immediate cardiac evaluation, as reversed R wave progression is highly indicative of cardiac disease, particularly ischemic heart disease with LAD stenosis (found in 58% of cases with this finding). 3

• T wave inversion in inferior leads (II, III, aVF) often reflects right ventricular infero-posterior wall involvement in arrhythmogenic cardiomyopathy, making this a concerning pattern that warrants comprehensive cardiac imaging. 1

• The prolonged QTc adds additional risk for malignant arrhythmias, particularly when combined with structural heart disease suggested by the other ECG abnormalities. 1, 2

Note on T Wave Inversion in aVR

• T wave inversion in aVR is actually NORMAL in adults - the normal T wave should be inverted in aVR in all adults over 20 years of age. 4 This finding should not contribute to your diagnostic concern.

Differential Diagnosis by Priority

1. Acute Coronary Syndrome with LAD Involvement

• Reversed R wave progression (where R waves decrease from V1→V2→V3→V4) is rare (0.3% prevalence) but highly specific for cardiac disease, with 41% having prior anterior MI and 17% having ischemic heart disease without MI. 3

• All patients with ischemic heart disease and reversed R wave progression had LAD artery stenosis in one study, making this a critical finding. 3

• T wave inversions in inferior leads (II, III) combined with poor R wave progression may indicate multi-vessel disease or wraparound LAD affecting both anterior and inferior territories. 1, 2

2. Arrhythmogenic Cardiomyopathy (AC)

• T wave inversions in inferior leads (II, III, aVF) often reflect RV infero-posterior wall involvement in AC, which is increasingly recognized as a distinct pattern. 1

• Poor R wave progression can occur in AC due to right ventricular structural changes, though this is less common than in ischemic disease. 1, 5

• The prolonged QTc may represent the arrhythmogenic substrate characteristic of this condition. 1

• However, a diagnosis based on imaging criteria with completely normal ECG should be considered suspicious in AC - the presence of ECG changes actually supports rather than contradicts this diagnosis. 1

3. Other Cardiomyopathies

• Dilated cardiomyopathy (7%) and hypertrophic cardiomyopathy (3%) can present with reversed R wave progression, though less commonly than ischemic disease. 3

• Left ventricular hypertrophy accounts for 14% of poor R wave progression cases and can be distinguished by standard voltage criteria. 5, 6

4. Non-Cardiac Causes (Less Likely but Important)

• Central nervous system events (intracranial hemorrhage) can cause deep T wave inversions with QT prolongation, though this typically affects precordial leads more than inferior leads. 1, 2

• Pulmonary embolism can produce T wave inversions (3% of reversed R wave progression cases) and should be considered if clinical context suggests. 3

Diagnostic Algorithm

Immediate Actions (Within 10 Minutes)

• Obtain serial ECGs and compare with any prior tracings to identify new changes versus chronic findings. 2

• Measure cardiac biomarkers (troponin) immediately, as this pattern may represent acute ischemia. 2

• Assess for symptoms: chest pain >20 minutes, dyspnea, palpitations, syncope, or family history of sudden cardiac death. 1, 2

First-Line Imaging (Within 24 Hours)

• Transthoracic echocardiography is mandatory to assess:
  • Left ventricular wall motion abnormalities (anterior and inferior walls)
  • Right ventricular size and function
  • Left ventricular hypertrophy
  • Regional wall motion abnormalities
  • Ejection fraction 1, 2

If Echocardiography is Non-Diagnostic

• Cardiac MRI with gadolinium enhancement should be performed to:
  • Detect subtle myocardial fibrosis or scarring
  • Assess for cardiomyopathy phenotypes
  • Evaluate both RV and LV involvement
  • Identify late gadolinium enhancement patterns 1, 2

Risk Stratification for Ischemia

• If age ≥30 years with risk factors for CAD, stress testing or coronary angiography may be warranted, particularly given the high association of reversed R wave progression with LAD stenosis. 1, 3

• The positive predictive value of poor R wave progression for CAD is only 7.3% in general populations, but reversed R wave progression (which is more specific) has much higher predictive value. 3, 7

Specific ECG Criteria Analysis

Poor R Wave Progression Definition

• Poor R wave progression is defined as R waves in V3 or V4 ≤2mm, though more specific criteria include RV2<RV1, RV3<RV2, or RV4<RV3 (reversed R wave progression). 3, 7

• Reversed R wave progression is more specific for cardiac pathology than simple poor R wave progression and should trigger more aggressive evaluation. 3, 6

T Wave Inversion Significance

• T wave inversion ≥1mm in depth in two or more contiguous leads (excluding aVR, III, and V1) is considered abnormal and warrants investigation. 1, 2

• T wave inversion in inferior leads (II, III, aVF) is uncommon even in athletes and requires further investigation to exclude cardiomyopathy. 1, 2

QTc Prolongation

• QTc ≥470ms in males or ≥480ms in females is considered prolonged and increases arrhythmic risk, particularly when combined with structural heart disease. 1

Common Pitfalls to Avoid

• Do not dismiss poor R wave progression as a normal variant without proper evaluation - while 24% of reversed R wave progression cases are normal, 76% have significant cardiac pathology. 3

• Do not attribute poor R wave progression solely to lead placement without confirming with repeat ECG - true reversed R wave progression persists with proper lead placement. 1, 7

• Do not overlook the combination of findings - while individual findings may have lower specificity, the combination of poor R wave progression + inferior T wave inversions + prolonged QTc significantly increases the likelihood of serious cardiac pathology. 2, 3

• Remember that T wave inversion in aVR is NORMAL and should not factor into your assessment of pathology. 4

• Do not assume this is chronic without comparison to prior ECGs - new T wave inversions with symptoms require immediate ACS evaluation. 2