What is the management approach for a patient with an RSR (Ragged S wave and R prime wave) pattern in lead V2 on an electrocardiogram (ECG)?

Management of RSR' Pattern in Lead V2 on ECG

The RSR' pattern in lead V2 requires a thorough evaluation to rule out pathological conditions, as it can represent either a normal variant or indicate underlying cardiac disease requiring specific management.

Understanding the RSR' Pattern

The RSR' pattern (also called ragged S wave and R prime wave) is characterized by:

• An initial R wave
• A deep S wave
• A terminal R' wave (or r' deflection)

This pattern can be seen in several conditions:

Normal Variant vs. Pathological Conditions

• Normal variant: In children, an rsr' pattern in V1 and V2 with normal QRS duration is considered a normal variant 1
• Incomplete RBBB: When QRS duration is between 110-120 ms in adults with RSR' morphology 1
• Complete RBBB: When QRS duration is ≥120 ms with RSR' morphology 1
• Ventricular aneurysm: RSR' pattern can indicate ventricular aneurysm, particularly when present in left surface leads 2
• Myocardial infarction scar: RSR' complex with wide QRS (≥110 ms) unrelated to bundle branch blocks can be a specific sign of myocardial infarction scar 3
• Brugada syndrome: Must be differentiated from benign RSR' patterns 4

Diagnostic Approach

1. Measure QRS duration:

   • <110 ms: Likely normal variant or incomplete RBBB
   • 110-119 ms: Incomplete RBBB 1
   • ≥120 ms: Complete RBBB or other pathology 1

2. Evaluate RSR' morphology:

   • Check if R' deflection is wider than initial R wave (typical for RBBB) 1
   • Assess S wave duration compared to R wave in leads I and V6 (S wave greater duration than R wave or >40 ms suggests RBBB) 1
   • Measure R peak time in lead V1 (>50 ms suggests RBBB) 1

3. Look for associated findings:

   • Frontal plane axis deviation
   • Evidence of ventricular hypertrophy
   • Q waves or other signs of prior infarction
   • ST-segment and T-wave abnormalities

Management Algorithm

1. If normal QRS duration (<110 ms) with RSR' in V2:

   • Likely normal variant, especially in children and young adults
   • Verify lead placement (high placement of V1-V2 can produce RSR' pattern) 4
   • No specific treatment needed if asymptomatic and no other abnormalities

2. If incomplete RBBB criteria met (QRS 110-119 ms):

   • Evaluate for underlying structural heart disease with echocardiography
   • Consider cardiac MRI if suspicion for ARVD/C or other cardiomyopathy
   • Follow-up ECGs to monitor for progression

3. If complete RBBB criteria met (QRS ≥120 ms):

   • Comprehensive cardiac evaluation including echocardiography
   • Evaluate for coronary artery disease if appropriate risk factors present
   • Consider stress testing if symptoms suggest ischemia
   • Monitor for development of bifascicular block or higher degrees of heart block 1

4. If RSR' pattern with evidence of myocardial infarction or aneurysm:

   • Comprehensive cardiac evaluation with echocardiography and possibly cardiac MRI
   • Appropriate medical therapy for coronary artery disease
   • Risk stratification for sudden cardiac death
   • Consider ICD if ejection fraction is severely reduced

Special Considerations

• Brugada syndrome: If RSR' pattern is accompanied by ST elevation in V1-V3, evaluate for Brugada syndrome, which requires specialized management and risk stratification 4
• Lead placement: Verify proper lead placement, as high placement of precordial leads can produce RSR' patterns that mimic pathology 4
• Dynamic changes: Serial ECGs may be valuable as some pathological conditions show dynamic changes

Common Pitfalls to Avoid

1. Misdiagnosing normal variants as pathology: Especially in children and young adults where RSR' patterns can be normal
2. Overlooking lead placement issues: High placement of V1-V2 leads commonly produces RSR' patterns
3. Missing underlying pathology: RSR' may be a marker of ventricular aneurysm or myocardial scar that requires further evaluation 2, 3
4. Focusing only on the RSR' pattern: The entire ECG should be evaluated for other abnormalities that may provide diagnostic clues

By following this systematic approach, clinicians can appropriately evaluate and manage patients with RSR' patterns in lead V2, distinguishing benign variants from those requiring further evaluation and treatment.