Bundle branch block

What it means

Block of conduction of electrical impulses along the Bundle of His or along one of its bundle branches.

The Bundle of His conducts the electrical impulse from the atrioventricular node into the ventricles. The Bundle of His divides into right and left bundle branches. A universal feature of a bundle branch block is a prolongation of the time required for depolarization of a portion of the ventricles, reflected in an abnormality of the QRS complex.

Rare diseases that can present with this13

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: Bundle-branch block