What marks the end of the rapid filling period in the heart?

The end of the rapid filling period in the heart is marked by diastasis. During the cardiac cycle, diastole is the phase when the heart relaxes and fills with blood. The rapid filling phase occurs right after the mitral valve opens, allowing blood to flow quickly from the left atrium into the left ventricle.

As the left ventricle fills, the pressure gradually equilibrates, leading the flow of blood to slow down; this transition initiates diastasis. At this point, the blood flow becomes less rapid, and the filling from the atrium to the ventricle stabilizes before the next atrial contraction occurs.

Diastasis is an important phase as it allows the heart to prepare for the next contraction without the ventricles becoming overly distended or overfilled. Understanding this timing helps in assessing diastolic function and overall heart health during echocardiographic evaluations.