Right atrium

RA is more difficult to estimate than LA. There are only a few echocardiographic measurements. In many cases, we look at the AP4CH to the ratio LA / RA: LA is normally slightly larger.

RA size

 MALEFEMALE
Mean ± SDMean ± SD
RA minor axis diameter (cm/m²)1.9 ± 0.31.9 ± 0.3
RA major axis diameter (cm/m²)2.5 ± 0.32.4 ± 0.3
(2D echo) RA volume (mL/m²)21 ± 625 ± 7

 

RA pressure

Inferior Vena Cava sizeEstimation RA pressure
Normal <21mm, collaps >50%3 mmHg (range 0–5 mmHg)
Borderline <21mm, collaps <50%8 mmHg (range 5–10 mmHg)
Borderline >21mm, collaps >50%8 mmHg (range 5–10 mmHg)
Dilated >21mm, collaps < 50% 15 mmHg (range 10- 20 mmHg)

 

Eur Heart J Cardiovasc Imaging. 2015 Mar;16(3):233-70