What is the significance and management of a tall R wave and positive T wave in leads V1 and V2 on an electrocardiogram (ECG)?

Significance and Management of Tall R Wave and Positive T Wave in Leads V1 and V2

A tall R wave with positive T wave in leads V1 and V2 most commonly indicates right ventricular hypertrophy, posterior myocardial infarction, or a normal variant with prominent anterior forces, requiring careful evaluation to determine the underlying cause.

Differential Diagnosis

1. Right Ventricular Hypertrophy (RVH)

• RVH causes displacement of the QRS vector toward the right and anteriorly, often with a delay in R-wave peak in right precordial leads 1
• Diagnostic criteria include:
  • R/S ratio ≥1 in lead V1 (tall R wave) 2
  • Right axis deviation in the frontal plane 1
  • R peak time >50 ms in lead V1 1
  • S waves of greater duration than R wave or >40 ms in leads I and V6 1

2. Posterior Myocardial Infarction

• Tall R waves in V1-V2 often represent Q waves of a posterior infarction 1
• Associated findings include:
  • Taller T waves in leads V1 and V2 compared to normal variants 3
  • Shorter T waves in V6 3
  • ST depression in leads V1-V3 may suggest inferobasal (posterior) myocardial ischemia, especially when the terminal T wave is positive 1

3. Normal Variant with Prominent Anterior Forces (PAF)

• Present in approximately 1% of normal individuals 2
• Usually has less prominent T waves in V1-V2 compared to posterior MI 3
• No associated ST segment abnormalities or clinical evidence of heart disease 3

4. Other Causes

• Right Bundle Branch Block (RBBB): characterized by QRS duration ≥120 ms, rSR' pattern in V1-V2, and wide S waves in leads I and V6 1
• Wolff-Parkinson-White syndrome type A: short PR interval and delta wave 2
• Hypertrophic cardiomyopathy: often with associated deep Q waves in lateral leads 2
• Acute right ventricular strain: in pulmonary embolism or other causes of acute pulmonary hypertension 2
• Dextrocardia: with associated global pattern changes 2
• Cardiac sarcoidosis with right ventricular involvement: characterized by R' wave in V1-V3 with surface area ≥1.65 mm² 4

Evaluation Algorithm

Step 1: Assess QRS Duration and Morphology

• If QRS ≥120 ms with rSR' pattern and wide S waves in I and V6, consider RBBB 1
• If QRS <120 ms with tall R wave in V1-V2, proceed to next steps 1

Step 2: Evaluate for Signs of Posterior Myocardial Infarction

• Look for ST depression in V1-V3 with positive terminal T wave 1
• Check for reciprocal changes in other leads (ST elevation in posterior leads V7-V9 if recorded) 1
• Assess for tall T waves in V1-V2 with shorter T waves in V6 3
• Review for evidence of inferior infarction (Q waves in II, III, aVF) which often accompanies posterior MI 1

Step 3: Assess for Right Ventricular Hypertrophy

• Check for right axis deviation in the frontal plane 1
• Look for R peak time >50 ms in lead V1 1
• Evaluate for right atrial abnormality (P pulmonale) 1
• Consider clinical conditions that might cause RVH (congenital heart disease, pulmonary hypertension, chronic lung disease) 1

Step 4: Consider Other Diagnoses

• Check PR interval (prolonged PR ≥220 ms with R' wave may suggest cardiac sarcoidosis) 4
• Evaluate for delta waves suggesting WPW syndrome 2
• Look for deep Q waves in lateral leads suggesting hypertrophic cardiomyopathy 2

Management Recommendations

If Posterior Myocardial Infarction is Suspected:

• Obtain posterior leads (V7-V9) to confirm ST elevation (>0.05 mV, or >0.1 mV in men <40 years) 1
• Urgent cardiac biomarkers and cardiology consultation 1
• Consider reperfusion therapy if acute 1

If Right Ventricular Hypertrophy is Suspected:

• Echocardiography to confirm RVH and assess for underlying cause 1
• Further cardiac imaging (CT, MRI) may be needed based on suspected etiology 1
• Treatment directed at underlying cause (pulmonary hypertension, congenital heart disease, etc.) 1

If Normal Variant is Suspected:

• Confirm absence of concerning symptoms, family history of sudden cardiac death, or other ECG abnormalities 1
• Consider echocardiography to rule out structural heart disease 1
• No specific treatment needed if confirmed as normal variant 1

Important Pitfalls and Caveats

1. Misplaced precordial leads can create false appearance of tall R waves in V1-V2 - verify proper lead placement 2

2. Acute myocardial infarction can sometimes present with a "giant R wave" (≥50% increase in R wave amplitude) in the affected territory during the acute phase - don't miss this finding 5

3. Brugada syndrome may mimic incomplete RBBB but has characteristic J-wave elevation and downsloping ST segment in V1-V2 - requires careful differentiation 1

4. In athletes, physiological adaptations can cause ECG changes that mimic pathology - interpret in clinical context 1

5. The presence of both tall R waves in V1-V2 and criteria for left ventricular hypertrophy may indicate biventricular hypertrophy 1

6. In children, an rSr' pattern in V1-V2 with normal QRS duration is often a normal variant and should not be misinterpreted as pathological 1