The QRS complex represents the passage of an electrical charge through which part of the heart?

The QRS complex reflects the depolarization of the ventricles in the heart, which is a critical component of the cardiac cycle. This complex occurs when the electrical impulse, originating from the heart's natural pacemaker, travels through the bundle branches located within the interventricular septum. It is during this phase that the ventricles contract, pumping blood to the lungs and the rest of the body.

While the atria also generate electrical impulses that are represented by other segments of the EKG, it is specifically the action of the bundle branches and the subsequent depolarization of the ventricles that create the QRS complex on the EKG tracing. This distinction is essential for understanding how electrical conduction corresponds to heart function and is a key concept in EKG interpretation.