What is the definition of diastolic dysfunction?

Diastolic dysfunction refers specifically to the heart's impaired ability to relax and fill properly during the diastolic phase of the cardiac cycle. In a healthy heart, diastole allows the chambers to expand and fill with blood before contraction occurs. When diastolic dysfunction is present, that relaxation is hindered, leading to inadequate filling of the ventricles and potential heart failure symptoms. This can often manifest in patients with conditions such as hypertension or left ventricular hypertrophy.

Options related to blood vessel elasticity or types of heart attacks do not address the specific mechanism by which diastolic dysfunction occurs. Arrhythmias, which refer to irregular heartbeats, are different cardiac abnormalities that do not specifically pertain to the filling and relaxation phases of the heart's functioning. Thus, the definition encompassing the heart's difficulty in relaxing captures the essence of diastolic dysfunction accurately.