Fig. 1

Measurement of the LAEDV and LVEDV via the biplane method to calculate the LACI index via two-dimensional echocardiography. In cases where an electrocardiogram is not simultaneously recorded during echocardiography or when it is difficult to identify the cardiac cycle during LACI measurement, the LAEDV can be considered the smallest LA volume, and the LVEDV can be considered the largest LV volume. Panel A: Measurement of the LV volume in the apical four-chamber view. Panel B: Measurement of the LV volume in the apical two-chamber view. Panel C: Measurement of LA volume in the apical four-chamber view. Panel D: Measurement of LA volume in the apical two-chamber view.