Left atrial diameter

LA AP diameter is a quick parasternal size cross-check and should be interpreted alongside indexed LA volume.

Clinically reviewed 24 May 2026 · EchoRapp clinical content

Simple approach

Use LA AP diameter as supporting context, not as the primary size diagnosis. Indexed LA volume is usually the better severity anchor.

Detailed tutorial

AP diameter is measured in parasternal long-axis view. It can underestimate asymmetric remodeling, especially when the atrium enlarges in the superior-inferior or medial-lateral direction.

  • Compare AP diameter with the selected indexed LA volume.
  • Confirm image alignment when AP diameter is unexpectedly small or large.
  • Use indexed volume for the final LA size summary when available.
Educational use only. MediRapp Academy content is provided for education and training. It is not medical advice and does not replace clinical judgment, institutional protocols, or the cited guideline documents. Always confirm values and recommendations against the current guidelines before clinical use.