In a basic EKG, what does the P wave represent?

The P wave in a standard EKG represents the depolarization of the atria, specifically the right atrium primarily, with some contribution from the left atrium. When the heart's electrical activity begins, it starts in the sinoatrial (SA) node located in the right atrium. The depolarization that initiates the contraction of the atria generates the P wave on the EKG.

It's important to recognize that while the P wave is primarily associated with the right atrial depolarization, it also reflects the electrical activity in the left atrium due to the proximity and interconnectedness of the atrial muscle fibers. Therefore, while the focus is on the right atrium, the left atrium is also involved in this process, but the key point is that it signifies the depolarization phase leading to atrial contraction.

This understanding of the P wave is crucial for interpreting EKGs and diagnosing conditions related to atrial function and rhythm.