What is diastolic dysfunction?

The proper function of the heart depends both on normal heart muscle contraction in systole and normal muscle relaxation in diastole. Improper relaxation of the left ventricle in diastole may impede the normal easy flow of blood returning from the lungs into the left ventricle. This is known as diastolic dysfunction, and results in the lungs becoming congested with blood (left-sided congestive heart failure). Congestive heart failure due to diastolic dysfunction frequently is associated with chronic hypertension but also occurs in the absence of hypertension as the normal heart ages.