What does the P wave on an EKG represent?

The P wave on an EKG represents atrial contraction, which is the result of electrical impulses originating from the sinoatrial (SA) node in the right atrium. When these impulses travel through the atria, they cause depolarization, leading to the contraction of the atrial muscles. This contraction is crucial for pushing blood from the atria into the ventricles, and the P wave reflects this specific electrical activity.

Understanding the P wave's role is important in interpreting heart rhythms and diagnosing various cardiac conditions. The shape and duration of the P wave can provide insights into the presence of atrial enlargement or other atrial abnormalities. The P wave is typically the first deflection on the EKG tracing, preceding the QRS complex, which represents ventricular contraction.

In addition to the P wave, the other options provided relate to different aspects of cardiac function or electrical activity. Ventricular contraction corresponds to the QRS complex, the resting state is represented by the baseline of the EKG when the heart muscle is not contracting, and the electrical impulse delay pertains to the PR interval extending from the end of the P wave to the start of the QRS complex, showing how long it takes for the impulse to travel from the atria to