Right Bundle Branch Block (RBBB)

What is right bundle branch block?

Every normal heart is gifted with a natural in-built electrical system. The electrical impulse generated from this system results in beating of the heart. The electrical system divides into 2 branches (called right and left bundle) at the level of the ventricle (bottom chambers of the heart).

The right bundle stimulates the right ventricle into action and the left bundle stimulates the left ventricle. If there is blockage in any of the branches, it results in the delayed activation of the supplied ventricle. This is reflected on the 12-lead ECG (electrical tracing of the heart) and is interpreted as either right or left bundle branch block.

 

How common is the right bundle branch block?

Right bundle branch block (RBBB) is not an uncommon finding in the general population. The prevalence increases with age – i.e. it is more commonly seen in elderly individuals. RBBB is also not an uncommon finding in young people, especially athletes. The prevalence of the condition in young, middle age and elderly individuals is believed to be 0.2%, 0.7% and 11.3% respectively

 

What is the significance of RBBB on an ECG?

RBBB is usually an incidental finding on an ECG, which would have been carried out for another reason. However, in the presence of symptoms like chest pain or shortness of breath or syncope, it might signify underlying heart or lung disorders such as:

  • Long standing right heart failure
  • Myocardial infarction (heart attack)
  • Congenital heart conditions (hole in the heart)
  • Long standing lung conditions affecting right side of the heart
  • Pulmonary embolism (clot in the lung)

RBBB seen in elderly individuals without heart problem could be due to the degenerative changes of the right bundle as a part of normal ageing process.

 

Does RBBB need further investigations and treatment?

As mentioned above, RBBB can be an incidental finding. If there are no symptoms associated, there is no need for further investigations and treatment. However, if associated with any of the above-mentioned symptoms, then further evaluation is required in the form of echocardiography (ultrasound scan of the heart).

On the other hand, left bundle branch block (LBBB) on the ECG may suggest underlying heart conditions, meaning that further investigations would be made.