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Figure 1 Biplane Methods With Which to Calculate LA Volume

(A) Biplane area length, A1 = left atrial (LA) area, 4-chamber view; A2 = LA area, 2-chamber view; L1 and L2: length from midplane of mitral annulus to superior LA, L = LA length, L1 or L2 whichever is shorter; (B) Biplane Simpson’s where the volume of the LA is calculated as the sum of the volume of each individual disc.