What causes bundle branch block?
For the left and right ventricles to contract at the same time, an electrical impulse must travel down the right and left bundle branches at the same speed. If there is a block in one of these branches, the electrical impulse must travel to the ventricle by a different route. When this happens, the rate and rhythm of your heartbeat are not affected, but the impulse is slowed. Your ventricle will still contract, but it will take longer because of the slowed impulse. This slowed impulse causes one ventricle to contract a fraction of a second slower than the other. The medical terms for bundle branch block are derived from which branch is affected. If the block is located in the right bundle branch, it is called right bundle branch block. If the block is located in the left bundle branch, it is called left bundle branch block. The block can be caused by coronary artery disease, cardiomyopathy, or valve disease. Right bundle branch block may also occur in a healthy heart. What are the symp