Obesity and left atrial function: state of the art

Obesity is an established risk factor for heart failure (HF), with every unit increase in body mass index, the risk of HF increases by 5-7%. Obesity can especially increase the risk for HF with preserved ejection fraction due to left atrial (LA) dysfunction caused by underlying systemic inflammation, chronic volume overload, and growth of epicardial adipose tissue. LA function can be assessed by measuring LA reservoir, conduit and booster, which correspond to physiological functions of LA filling during filling phase of cardiac cycle, LA pushing blood into left ventricle passively, and LA contraction to push the blood into left ventricle, respectively. Existing data show strong prognostic ability of LA strain reservoir for cardiovascular mortality and HF hospitalization. Several studies have also suggested that obesity in itself can cause reduction in LA strain and deterioration of LA function. Whether various weight loss interventions for patients with obesity can minimize and reverse LA remodeling and dysfunction remains unclear. In this review, we summarize the evidence regarding the impact of obesity on LA function, and discuss the impact of various weight reduction techniques on LA strain.