What is the phase of ventricular relaxation?

The phase of ventricular relaxation is known as diastole. Diastole occurs after ventricular systole, which is the phase of ventricular contraction. During diastole, the ventricles relax and fill with blood. The first part of diastole is known as early diastole, during which the atrioventricular valves open and blood flows from the atria into the ventricles. The second part of diastole is known as late diastole, during which the ventricles continue to fill with blood and the pressure in the ventricles increases. At the end of diastole, the ventricles contract and systole begins.