What does the "P" wave signify in an EKG?

The "P" wave on an EKG represents atrial depolarization, which is a crucial part of the cardiac cycle. During this phase, the electrical impulse generated in the sinoatrial (SA) node causes the atria to contract and push blood into the ventricles. This is the first component seen on the EKG strip and indicates that the atria are actively preparing for the next phase of the heart's function.

Understanding the significance of the "P" wave is essential for recognizing normal heart function as well as identifying potential atrial issues. For instance, the absence of a "P" wave might suggest problems such as atrial fibrillation, where the atria do not properly depolarize and contract. This understanding is foundational for interpreting EKGs and diagnosing cardiac conditions effectively.