What does the P wave on an EKG represent?

The P wave on an EKG represents atrial depolarization, which is the electrical activation of the atria that triggers their contraction. This phase is crucial for the effective filling of the ventricles with blood before they contract. During this process, the electrical signal originates from the sinoatrial (SA) node, travels through the atria, and culminates in atrial contraction.

Understanding the P wave is fundamental to interpreting EKGs because any abnormalities in its shape or duration can indicate underlying cardiac issues, such as atrial enlargement or other atrial disturbances. The P wave typically precedes the QRS complex, which represents ventricular depolarization, ensuring a rhythmic and coordinated contraction of the heart. Recognizing this relationship enhances the ability to assess the overall heart rhythm and function.