What condition does diastolic dysfunction affect in the heart?

Diastolic dysfunction primarily affects compliance, which refers to the ability of the heart to expand and fill with blood during the diastolic phase of the cardiac cycle. In diastolic dysfunction, the heart is typically stiff or less compliant, leading to impaired filling of the ventricles with blood. This can occur in conditions such as hypertension or myocardial fibrosis, where the heart muscle becomes less able to stretch adequately to accommodate incoming blood.

As the heart’s compliance decreases, it struggles to fill properly, which can cause increased pressures in the left atrium and pulmonary circulation, leading to symptoms of heart failure, even if the ejection fraction (the percentage of blood that is pumped out of the heart with each contraction) remains normal. Since compliance directly influences how well the heart can fill with blood, it is the key factor affected in diastolic dysfunction.