How to manage 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

An RSR' pattern in lead V2 on ECG most commonly represents incomplete right bundle branch block (RBBB) and requires evaluation for underlying cardiac pathology, with management focused on identifying any associated conduction disorders or structural heart disease.

Understanding the RSR' Pattern

• RSR' pattern in V1-V2 is characterized by an initial small r wave, followed by an S wave, and then a terminal R' wave (r') deflection that is usually wider than the initial r wave 1
• This pattern can represent incomplete RBBB when QRS duration is between 110-119 ms, or complete RBBB when QRS duration is ≥120 ms 1
• The pattern may also be a normal variant, especially in children and young adults 1, 2

Initial Assessment

• Evaluate for symptoms such as syncope, pre-syncope, palpitations, or dyspnea which may indicate underlying pathology 1
• Assess for family history of sudden cardiac death or inherited arrhythmia syndromes 1
• Measure QRS duration:
  • <110 ms: Likely normal variant or non-specific intraventricular conduction delay 1
  • 110-119 ms: Consistent with incomplete RBBB 1
  • ≥120 ms: Complete RBBB requiring further evaluation 1

Differential Diagnosis

The RSR' pattern in V2 may represent:

• Incomplete or complete RBBB - most common cause 1
• Normal variant, especially in children and young adults 1, 2
• Brugada syndrome - distinguished by coved ST-segment elevation ≥2 mm and terminal T-wave inversion 1
• Ventricular aneurysm - especially if present in left-sided leads 3
• Right ventricular hypertrophy or enlargement 4
• Arrhythmogenic right ventricular dysplasia/cardiomyopathy 2

Diagnostic Algorithm

1. Confirm ECG findings:

   • Verify correct lead placement 1
   • Assess QRS duration and morphology criteria 1
   • Use the "Corrado index" to differentiate from Brugada pattern (STJ/ST80 ratio <1 in normal RSR' vs >1 in Brugada) 1

2. Further testing based on clinical suspicion:

   • Echocardiogram to evaluate for structural heart disease if:

     • Complete RBBB (QRS ≥120 ms) 1
     • Symptoms of heart failure or arrhythmia 1
     • Abnormal physical examination 1

   • Consider high precordial lead ECG (V1-V2 in 2nd or 3rd intercostal space) if Brugada pattern is suspected 1

3. Specialized testing when indicated:

   • Exercise testing to evaluate chronotropic response and QRS changes with exertion 1
   • 24-hour Holter monitoring if symptomatic arrhythmias are suspected 1
   • Cardiac MRI if arrhythmogenic right ventricular cardiomyopathy is suspected 2

Management Recommendations

• Asymptomatic patients with normal QRS duration (<110 ms):

  • No specific treatment required 4, 2
  • Reassurance and routine follow-up 2

• Patients with incomplete RBBB (QRS 110-119 ms):

  • If asymptomatic with normal cardiac evaluation, no specific treatment needed 1
  • Annual follow-up to monitor for progression 1

• Patients with complete RBBB (QRS ≥120 ms):

  • Evaluate for underlying structural heart disease 1
  • Monitor for development of higher-degree conduction disorders 1
  • Consider referral to cardiology 1

• Patients with concerning features:

  • Refer to an electrophysiologist if:
    • Brugada pattern is identified 1
    • Symptoms of syncope or pre-syncope are present 1
    • Family history of sudden cardiac death 1
    • Evidence of progressive conduction disease 1

Special Considerations

• The RSR' pattern alone has poor sensitivity (36.1%) and moderate specificity (80%) for detecting atrial septal defects in children 5
• Brugada syndrome requires specific management and may necessitate ICD placement in high-risk patients 1
• Consider potential medication effects or electrolyte abnormalities that may accentuate conduction abnormalities 1