At what part of the cardiac conduction system does the electrical impulse travel most rapidly?

Purkinje Fiber

Explanation:

In normal circumstances, the SA (sinoatrial) node the heart natural pacemaker, produces electrical activity automatically. This electrical impulse is transmitted across the whole right atrium and into the bundle of Bachmann to the left atrium, arousing the atria's myocardium to contract. And the part through which the electrical impulse travel most rapidly is called Purkrnje fibers, which is a specialized conducting fiber consisting of electrically excitable cells and these conduct cardiac action potentials more quickly and efficiently than any other cells in the heart.