What does the QRS complex represent?

The QRS complex is an essential part of the electrocardiogram (ECG) that specifically represents the depolarization of the ventricles. During this phase, the electrical impulses spread throughout the ventricles, leading to their contraction and subsequent pumping of blood to the lungs and the rest of the body.

While it is true that the QRS complex follows the atrial depolarization (which is represented by the P wave), the complex itself does not indicate the repolarization of the atria as part of its primary definition. Instead, the atrial repolarization occurs concurrently during the QRS complex but is not visually displayed on the ECG since it is obscured by the much larger QRS wave.

Thus, the QRS complex primarily emphasizes the ventricular depolarization, which is crucial for the understanding of the cardiac cycle and pathology related to electrical conduction in the heart. Understanding this distinction is vital for interpreting ECGs accurately in both clinical and athletic settings.