Bundle branch block is a condition in which there's a delay or blockage along the pathway that electrical impulses travel to make your heart beat. It sometimes makes it harder for your heart to pump blood efficiently through your body.
The delay or blockage can occur on the pathway that sends electrical impulses either to the left or the right side of the bottom chambers (ventricles) of your heart.
Bundle branch block might not need treatment. When it does, treatment involves managing the underlying health condition, such as heart disease, that caused bundle branch block.
Symptoms
Rarely, signs and symptoms may include fainting (syncope) or feeling as if you're going to faint (presyncope).
Causes
Left bundle branch block
- Heart attack (myocardial infarction)
- High blood pressure (hypertension)
- Infection of the heart muscle by bacteria or virus (myocarditis)
- Thickened, stiffened or weakened heart muscle (cardiomyopathy)
Right bundle branch block
- Blood clot in the lungs (pulmonary embolism)
- Heart attack (myocardial infarction)
- Heart defects that are present at birth (congenital) — such as a hole in the wall separating the upper chambers of the heart (atrial septal defect)
- High blood pressure in the pulmonary arteries (pulmonary hypertension)
- Infection of the heart muscle by bacteria or virus (myocarditis)
RBBB (Right bundle branch block) is a blockage of electrical impulses to the heart’s right ventricle. The right ventricle is located in the lower right part of the heart. With right bundle branch block, the electrical signal doesn’t travel to the right ventricle the way it should.