What does late phase of ventricular filling correspond with?

The late phase of ventricular filling corresponds to atrial contraction. During this phase, the ventricles are largely filled with blood, and the atria contract to push additional blood into the ventricles, completing their filling. This process ensures that the ventricles are adequately filled with blood before they contract. The pressure generated by the contraction of the atria contributes to the final portion of ventricular diastole, which is crucial for optimal cardiac output.

Understanding this phase is important because it highlights the role of the atria in cardiac function, particularly in conditions where atrial contraction may be impaired, such as in atrial fibrillation where the lack of effective atrial contractions can lead to decreased ventricular filling and potential heart failure.