What is the pathophysiology of diastolic dysfunction (HFrEF)?

• A. Structural and cellular alterations leading to LV inability to relax
• B. Cardiomyocyte loss leading to LV reduced pumping
• C. Ventricular dilation due to volume overload
• D. Myocardial infarction causing arrhythmia

Answer: (A)

Diastolic dysfunction arises when the left ventricle becomes stiff or relaxes poorly, so filling during diastole is impaired. Structural and cellular changes—such as myocardial hypertrophy, interstitial fibrosis, and abnormalities in calcium handling—make the ventricle less compliant and slower to relax. This leads to higher filling pressures and congestion, often with a preserved ejection fraction because systolic pumping is not the primary problem.

In contrast, the other descriptions point to issues more characteristic of systolic failure: loss of cardiomyocytes with reduced pumping ability, dilation from volume overload, or ischemia‑related problems like myocardial infarction causing arrhythmias.