What is the relaxation phase of the cardiac cycle called?

The relaxation phase of the cardiac cycle is referred to as diastole. During diastole, the heart muscles relax after contraction (systole) and allow the chambers of the heart to fill with blood. This phase is crucial for maintaining adequate blood volume in the heart, which is essential for effective circulation.

During diastole, the atria fill with blood from the veins, and as pressure builds, the atrioventricular (AV) valves open, allowing blood to flow from the atria into the ventricles. This filling phase is vital for ensuring that when the ventricles contract during systole, they have a sufficient volume of blood to pump throughout the body.

Understanding this concept is fundamental in cardiology, as it relates to the heart's efficiency and overall function. Monitoring and assessing diastolic function can reveal important information about cardiac health, particularly in conditions that affect the heart's ability to relax and fill properly.