Explaining Incomplete Right Bundle Branch Block (RBBB) to a Patient
An incomplete right bundle branch block is a minor delay in the electrical signal traveling through the right side of your heart that usually doesn't cause symptoms or require treatment in most people.
What is Incomplete Right Bundle Branch Block?
To understand this condition, let's break it down:
- Your heart has an electrical system that coordinates heartbeats
- This system includes specialized pathways called "bundles" that carry electrical signals
- The right bundle branch carries signals to the right side of your heart
- In incomplete right bundle branch block (IRBBB), there's a slight delay in this signal, but not a complete blockage
The main difference between incomplete and complete RBBB is the degree of delay:
- Incomplete RBBB: QRS duration between 110-119 milliseconds 1
- Complete RBBB: QRS duration ≥120 milliseconds 1
How Common Is It?
- IRBBB is found in about 4.7% of men and 2.3% of women in the general population 2
- It's more common in men and tends to increase with age 3
- Athletes often have IRBBB as a normal finding 4
What Causes It?
IRBBB can occur:
- As a normal variant in healthy people
- Due to electrode placement during ECG recording
- In people with certain chest wall configurations (like pectus excavatum)
- As a result of normal aging
- Rarely, as an early sign of heart disease
Is It Dangerous?
The good news is that unlike complete RBBB, incomplete RBBB:
- Is generally considered benign 4, 3
- Is not associated with increased cardiovascular risk or mortality 3, 2
- Doesn't typically require treatment or further testing if you have no symptoms or other heart problems 4
When Should You Be Concerned?
You should discuss further evaluation with your doctor if you have:
- Symptoms like fainting, chest pain, or shortness of breath
- A family history of heart disease
- Other heart conditions
- IRBBB that progresses to complete RBBB (which happens in about 5.1% of cases over 11 years) 5
Follow-up and Monitoring
- If you have no symptoms and no other heart problems, typically no special follow-up is needed
- Your doctor may recommend periodic ECGs to monitor for any changes
- If you have other heart conditions, your doctor will focus on managing those conditions
Key Takeaway
Most people with incomplete right bundle branch block lead normal lives without any symptoms or complications related to this finding. It's often discovered incidentally during an ECG done for other reasons and generally doesn't require specific treatment or lifestyle changes.