Dilated if bigger than LA
A4C – Measure minor (width) and major (length) axis. Planimetry RA.
Assume it is 10 or
Measure IVC in inspiration and expiration.
Obviously measuring it directly via a CVC is more accurate.
Normal structures which may be seen in RA
Eustachian valve – thin flap at junction of IVC and RA. Size and mobility variable.
Chiari network – web across RA in 2% population. Of no significance.