Typically, where in the heart is a pacemaker located?

Typically, the heart’s natural pacemaker is located in the right atrium. More precisely, it is the sinoatrial (SA) node, a small cluster of specialized cardiac muscle cells near the opening of the superior vena cava.

The SA node generates electrical impulses automatically. These impulses spread across the atria, making them contract and push blood into the ventricles. The signal then reaches the atrioventricular (AV) node and travels through the heart’s conduction system to coordinate ventricular contraction.

A common mix-up is confusing the natural pacemaker with an implanted pacemaker. An artificial pacemaker is a device usually placed beneath the skin of the chest, with leads positioned inside the heart; it is not itself located in the right atrium. Another nearby structure, the AV node, also helps regulate electrical conduction but is not the heart’s primary pacemaker under normal conditions.

The SA node was identified in 1907 by British researchers Arthur Keith and Martin Flack. Its activity normally establishes sinus rhythm, allowing the heart to beat in a coordinated pattern.