How do E/A ratio and e' velocity contribute to diastolic function assessment, and what are typical interpretive patterns?

• A. E/A ratio indicates E/A ratio alone defines diastolic function; e' is not useful.
• B. E/A ratio indicates early vs atrial diastolic filling; e' reflects diastolic relaxation; patterns: Grade I relaxational with E/A<1 and reduced e' (low); pseudonormal E/A around 1-1.5 with elevated E/e'; restrictive E/A≥2 with high E/e'.
• C. E/A ratio only reflects systolic function.
• D. e' velocity is not related to diastolic function.

Answer: (B)