Which part of the ECG represents atrial contraction?

The P wave on an ECG represents atrial contraction, also known as atrial depolarization. This phase occurs when the electrical impulse originating from the sinoatrial (SA) node spreads through the atria, causing them to contract and push blood into the ventricles. The P wave is crucial for understanding the electrical activity of the heart, as it indicates the initiation of the cardiac cycle.

Observing the P wave can provide important insight into the heart's rhythm and function. For instance, abnormalities in the P wave's shape or duration can indicate conditions such as atrial enlargement or dysfunction. Thus, recognizing that the P wave signifies atrial contraction is fundamental knowledge in interpreting ECG readings.