Fig. 2

Left atrioventricular coupling index (LACI). A Schematic illustration of the left atrioventricular coupling index (LACI), which is defined as a ratio between left atrial (LA) and left ventricular (LV) end-diastolic volume index (EDVI). Proportional enlargement of LA EDVI leads to an increase of LACI. B LACI indicating differences of LA (red/green) and LV (yellow) volume ratio in 2- and 4-chamber views of a patient with and without a major adverse clinical event (MACE), respectively