The bundle of nerve fibers that conveys the heart’s electrical pacing impulse from the atrioventricular (av) node to the ventricles, also called the bundle branches.
The short trunk portion of the bundle before it splits into the right branch and left branch is the main bundle of His. The German physician Wilhelm His (1863–1934) discovered the bundle branches in 1893. Doctors may use this term and the term bundle branch interchangeably.
For further discussion of cardiovascular structure and function, please see the overview section “The Cardiovascular System.”