Which electrical activity does a P wave represent?

The P wave on an electrocardiogram (EKG) specifically represents atrial depolarization. This is the physiological process that occurs when electrical impulses arise in the sinoatrial (SA) node, leading to the contraction of the atria. During depolarization, the atrial muscle cells become more positive and prepare to contract, which is crucial for the proper functioning of the heart as it fills the ventricles with blood.

Understanding this is essential, as the P wave is the first deflection in the EKG waveform, providing vital information about the heart's electrical activity. It is important in assessing the relationship between atrial activity and overall cardiac function, especially in diagnosing certain types of arrhythmias or atrial enlargement.