Left atrial size increases with body mass index in children.

Objectives: To evaluate the association between body mass index (BMI) z-score and left atrial (LA) size in childhood and to determine whether LA size differs between healthy weight (HW), overweight (OW) and obese (OB) children.

Background: LA enlargement is an independent risk factor for adverse cardiovascular outcomes. BMI is associated with LA size in adults but this may be mediated by co-morbidities that accompany adult obesity.