From the Guidelines
Retrograde Sinus Rhythm (RSR) in leads V1 and V2 is indicative of a Right Bundle Branch Block (RBBB).
Key Diagnostic Criteria
The following criteria are used to diagnose RBBB:
- rsr, rsR, or rSR pattern in leads V1 or V2, with the R or r deflection usually wider than the initial R wave 1
- S wave of greater duration than R wave or greater than 40 ms in leads I and V6 in adults 1
- Normal R peak time in leads V5 and V6 but greater than 50 ms in lead V1 1
Investigation and Management
In patients with RSR in leads V1 and V2, further investigation and management should focus on evaluating the underlying cause of the RBBB, such as cardiac structural abnormalities or conduction system disease 1.
Relevant Investigations
- Electrocardiogram (ECG): to confirm the diagnosis of RBBB and evaluate for other conduction abnormalities 1
- Echocardiogram: to evaluate cardiac structure and function 1
- Exercise stress test: to evaluate for signs of ischemia or conduction system disease 1 It is essential to note that the presence of RBBB may not necessarily require specific treatment, but rather management of the underlying condition causing the conduction abnormality 1.
From the Research
Investigations for Retrograde Sinus Rhythm (RSR) in leads V1 and V2
The following investigations are indicated for RSR in leads V1 and V2:
- Electrocardiographic algorithm for differential diagnosis, as proposed by 2
- Analysis of the ST segment and r' width to identify true Brugada pattern ECGs, as described by 3
- High precordial lead ECGs to identify true Brugada pattern ECGs, as suggested by 3 and 4
- Pharmacological test with sodium channel blockers to disclose the typical Brugada pattern, as mentioned by 4
- Exclusion of conditions that can mimic Brugada pattern, such as right bundle branch block, early repolarization, acute myocardial ischemia, pericarditis, hypercalcemia, hyperkalemia, hypothermia, and primary right ventricular diseases, as listed by 4
- Genetic testing to identify mutations in the SCN5A gene or other genes, as discussed by 4
- Programmed ventricular stimulation for risk stratification, as debated by 4
- Regular cardiology follow-up and 12-lead Holter monitoring, as recommended by 4
Key Considerations
- The presence of an rSr' pattern in leads V1 and V2 can be a normal variant or a sign of an underlying cardiac condition, such as Brugada syndrome or arrhythmogenic right ventricular dysplasia, as noted by 2 and 5
- The diagnosis of Brugada syndrome should be restricted to patients with diagnostic ECG changes and a history of symptoms, as stated by 4
- Asymptomatic subjects with a Brugada ECG pattern should receive adequate information and follow-up, as recommended by 4