In systolic heart failure, what happens to ejection fraction?

• A. It is preserved
• B. It is unchanged
• C. It is variable
• D. It is reduced

Answer: (D)

In systolic heart failure, the heart’s ability to contract and eject blood is impaired. Ejection fraction (EF) is the percentage of blood in the left ventricle that is pumped out with each beat, calculated as stroke volume divided by end-diastolic volume. When contraction is weak, stroke volume falls. The ventricle often dilates, increasing the end-diastolic volume, so the amount ejected becomes a smaller fraction of what was present. The result is a reduced ejection fraction. Typically, normal EF is about 55–70%, and systolic heart failure is characterized by EF falling below the normal range (often under ~40%). By contrast, preserved EF is seen in diastolic dysfunction, where filling is impaired but contraction remains relatively intact.