P wave

Definition

The P wave is the first wave in an electrocardiogram (ECG or EKG), representing the depolarization of the atria in response to an electrical impulse from the sinoatrial node. This process initiates atrial contraction, contributing to blood flow into the ventricles.

Related terms

Electrocardiogram (ECG or EKG): A test that measures the electrical activity of the heart to show how fast your heart is beating and if its rhythm is steady or irregular.

Depolarization:

A change within a cell during which the cell undergoes a shift in electric charge distribution, resulting in less negative charge inside the cell.

Sinoatrial node: Often called the heart's natural pacemaker, it generates electrical impulses that initiate each heartbeat