What does the P wave represent in an EKG?

The P wave in an electrocardiogram (EKG) represents atrial depolarization. This event occurs when the electrical impulse generated in the sinoatrial (SA) node spreads through the atria, causing them to contract and push blood into the ventricles. The P wave is typically the first deflection in the EKG waveform and is visualized as a small upward deflection.

Understanding the function of the P wave is essential because it indicates normal atrial electrical activity and proper functioning of the heart's pacemaker system. Abnormalities in the P wave can suggest issues with atrial size, conduction, or rhythm, providing critical insight into the overall health of the heart.