Which method of measuring left atrial size is most recommended and most accurate?

Comprehensive and Detailed Explanation From Exact Extract:

Biplane disk summation (Simpson’s method) of left atrial (LA) volume, indexed to body surface area, is the most accurate and recommended method for assessing LA size. This method accounts for the asymmetrical shape of the LA and provides reproducible volume measurements.

3D imaging can provide even more precise volume data but is less widely available and less standardized. Linear dimension and planimetry are less accurate because they do not fully represent LA size.

ASE chamber quantification guidelines strongly recommend biplane volume measurement for LA size assessment in clinical practice【12:ASE Chamber Quantification Guidelines†p.90-95】【16:Textbook of Clinical Echocardiography, 6e†p.120-125】.