What is bundle branch block?
Normally, the electrical impulse travels down both the right and left branches at the same speed. Thus, both ventricles contract at the same time. But occasionally, there’s a block in one of the branches, and electrical impulses are slowed or blocked as they travel through the specialized conducting tissue in the ventricles (His). Usually a person with bundle branch block shows no symptoms, but this block shows up on the electrocardiogram (ECG or EKG) as an abnormality. If you have bundle branch block, it may have only been noticed when you had an ECG. You may feel fine, although some people may either faint (syncope) or feel as if they’re going to faint (presyncope). If both bundles are diseased, heart block may result, producing syncope or presyncope. When this happens, the heartbeat may be so slow that an artificial pacemaker is implanted. Bundle heart block may be caused by damage to the heart muscle resulting from a heart attack.
