What is the treatment for right bundle branch block (RBBB)?

From the Guidelines

Right bundle branch block (RBBB) typically does not require specific treatment when it occurs in isolation without symptoms or underlying heart disease. Most patients with RBBB remain asymptomatic and can lead normal lives without any intervention. However, if RBBB is associated with an underlying cardiac condition such as coronary artery disease, heart failure, or pulmonary hypertension, treatment should focus on managing that primary condition rather than the conduction abnormality itself. For patients with symptomatic bradycardia due to high-degree AV block with RBBB, a permanent pacemaker may be necessary, as recommended by the 2018 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay 1.

In cases where RBBB is part of a bifascicular block (RBBB plus left anterior or posterior fascicular block) and causes symptoms, pacemaker implantation might be considered, especially if there is evidence of intermittent complete heart block. The 2018 ACC/AHA/HRS guideline also emphasizes the importance of shared decision-making and patient-centered care in treatment decisions for patients with bradycardia and cardiac conduction delay 1. Regular cardiac follow-up is recommended for patients with newly diagnosed RBBB to monitor for progression to more severe conduction disorders. RBBB itself doesn't impair cardiac function significantly because the electrical impulse can still reach the right ventricle through muscle-to-muscle conduction, albeit with a slight delay, which explains why isolated RBBB rarely causes symptoms or requires specific intervention.

Some key points to consider in the management of RBBB include:

• The presence of underlying cardiac conditions that may require separate management
• The symptoms associated with RBBB, such as bradycardia or heart block
• The potential need for pacemaker implantation in certain cases
• The importance of regular cardiac follow-up to monitor for progression of conduction disorders
• The role of shared decision-making and patient-centered care in treatment decisions, as emphasized in the 2018 ACC/AHA/HRS guideline 1.

It's also worth noting that the 2019 guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay provides additional recommendations for the management of RBBB, including the use of permanent pacing in patients with acquired second-degree Mobitz type II atrioventricular block, high-grade atrioventricular block, or third-degree atrioventricular block not caused by reversible or physiologic causes 1. However, the highest quality and most recent study, which is the 2019 guideline, should be prioritized when making treatment decisions 1.

From the Research

Treatment for Right Bundle Branch Block (RBBB)

The treatment for RBBB depends on the underlying cause and the presence of symptoms. Here are some key points to consider:

• Permanent His bundle pacing (HBP) has been shown to be effective in patients with RBBB and heart failure, with significant narrowing of QRS duration and improvement in left ventricular function 2.
• HBP has been associated with improvement in New York Heart Association functional class and increase in left ventricular ejection fraction in patients with RBBB and reduced left ventricular ejection fraction 2.
• The diagnosis of RBBB is typically made using electrocardiography (ECG), and the concordance in diagnosis between primary care researchers and cardiologists has been shown to be very good, especially for complete RBBB 3.
• Cardiac resynchronization therapy (CRT) is a well-established therapy for patients with cardiomyopathy, but its effectiveness in patients with RBBB is limited 2, 4.
• Left bundle branch pacing with optimization of cardiac resynchronization treatment may serve as a new CRT strategy, but its effectiveness in patients with RBBB is not well established 4.

Key Considerations

• The majority of patients with RBBB are asymptomatic, and the presence of symptoms such as coronary heart disease and hypertension is relatively low 5.
• The risk of cardiovascular mortality is higher in patients with RBBB, and further examination is indicated in each case 5, 6.
• The treatment of underlying disease is crucial in patients with RBBB, and specific therapy such as CRT may be available in certain cases 2, 6.