Final answer:
Diastolic heart failure is referred to as heart failure with preserved ejection fraction. It occurs when the heart muscle becomes stiff and loses its ability to relax properly, leading to inadequate oxygen supply to the body.
Step-by-step explanation:
Diastolic heart failure is also referred to as heart failure with preserved ejection fraction (option e). Diastolic heart failure occurs when the heart muscle becomes stiff and loses its ability to relax properly during the filling phase of the cardiac cycle. This impairs the heart's ability to fill with blood, leading to inadequate oxygen supply to the body.