Research suggests that left atrium size as measured by an echo-cardiograph may be linked to cardiovascular disease.

When an OSA event occurs, an attempt is made to breathe with an obstructed airway and the pressure inside the chest is suddenly lowered.

Characterizing the size of the left atrium according to its volume is preferred over a single linear dimension since enlargement can be different for different directions.

For example, because of the smaller distance in the thoracic cavity between the sternum and spine, compared to the other directions, less room exists for enlargement of the left atrium along the anteroposterior axis.

[9] By approximating the shape of the left atrium as an ellipsoid, its volume can be calculated from measurements of its dimensions along three perpendicular directions.