Certified EKG Technician (CET) Practice Exam 2025 – Comprehensive Test Prep

Atrial depolarization is represented on an EKG by the P wave. This wave corresponds specifically to the electrical activity associated with the contraction of the atria, the two upper chambers of the heart.

During atrial depolarization, the heart's action potential stimulates the atrial musculature, leading to muscle contraction. This electrical activity generates a wave that is visualized as the P wave on the EKG graph. The P wave typically appears as a small, upward deflection before the larger QRS complex.

Understanding that each component of the EKG waveforms represents specific electrical activities within the heart is crucial for interpreting EKGs. The QRS complex represents ventricular depolarization, while the T wave signifies ventricular repolarization. The term "digitized output" does not refer to specific electrical events in the heart, but rather how EKG data may be processed or displayed. Therefore, the P wave is the correct representation of atrial depolarization on an EKG.