Why is diastolic dysfunction important in heart failure with preserved EF (HFpEF), and how is echo used to diagnose it?

• A. HFpEF stems from diastolic dysfunction and elevated filling pressures; echo uses E/e', LA size, TR velocity, and diastolic indices to estimate filling pressures and HFpEF likelihood.
• B. HFpEF is due to systolic dysfunction; echo uses LVEF only.
• C. HFpEF is unrelated to diastolic function; echo diagnosis uses valve morphology alone.
• D. HFpEF is diagnosed by chest X-ray.

Answer: (A)