Fig. 2.

Contouring of Left and Right Atrial Dimensions. Maximal left atrial volume is estimated using the biplane area-length method (LAV = [8 x (2-chamber area) x (4-chamber area)]/3πL, where L is the shorter of the two left atrial length in the two views). Measurements were taken in the four- and two-chamber views, at the end of ventricular systole (a frame before opening of the mitral valve). Pulmonary veins and atrial appendage were excluded. Left atrial length was measured from the mid-point of the mitral annulus to the superior aspect of the left atrium. Right atrial area was determined in the four-chamber view