Impulse of heart beat originates from:

An electrical stimulus is generated by the sinoatrial node, or SA node. This is a small mass of specialized tissue located in the right atrium of the heart. Related Theory:- The AV node gathers the electrical impulse from $S A$ node and, after a brief delay, allows it to pass through to the ventricles. This brief delay in the transmission of the electrical signal through the AV node is critical to a normal heartbeat and the efficient functioning of the heart.