Reference Ranges & Partition Values for LA Volume Index (mL/m2)
LAVI (mL/m2)
Reference Range
16-28
Mildly Abnormal
29-33
Moderately Abnormal
34-39
Severely Abnormal
≥40
LA Volume & LA Volume Index (Biplane Area-Length Method)
When left atrial (LA) size is measured clinically, LA volume determinations are preferred over linear measurements since they allow more accurate assessment of the asymmetric remodeling of the LA chamber. Moreover, the strength of the relationship between cardiovascular diseases is stronger for LA volume than for LA linear dimensions.
LA size should be measured at the end-ventricular systole (maximum LA size). Foreshortening should be avoided. When planimetry is performed, LA confluences of the pulmonary veins and the LA appendage should be excluded. The length, L, remains the LA long-axis length determined as the distance of the perpendicular line measured from the middle of the plane of the mitral annulus to the superior aspect of the LA. In the area-length formula the length is measured in both the 4- and 2-chamber views and the shortest of these 2 length measurements is used in the formula.
Although there are gender differences in LA size, these are completely accounted for once indexed to body size, such as body surface area (BSA).
LA Volume
=
8
3π
*
A1 * A2
L
= (0.85) *
A1 * A2
L
LAVI
=
LA Volume
BSA
Variable
Definition
Input
A1
Max. planimetered LA area in apical 4-chamber (A4C) view
A2
Max. planimetered LA area in apical 2-chamber (A2C) view
L
Length measured from back wall to line across mitral valve hinge points (cm)
Weight
Weight (kg or lb)
Height
Height (cm or in)
Output
LA Volume
Left Atrial Volume
LAVI
Left atrial volume indexed to Body Surface Area (BSA)
References
Lang RM, et al. Recommendations for chamber quantification. J Am Soc Echocardiogr 2005;18:1440-1463.
Lester SJ, et al. Best method in clinical practice and in research studies to determine left atrial size. Am J Cardiol 1999; 84:829-32.
Pritchett AM, Redfield MM, et al. Left atrial volume as an index of left atrial size: a population-based study. J Am Coll Cardiol 2003; 41:1036-43.
Developer: Edward Brawer