DB10 Right Atrial Reservoir Dysfunction: An Early Manifestation of Right Heart Remodeling in Obesity

Abstract

Obesity is associated with cardiac remodeling and increased cardiovascular risk. While left ventricular changes have been extensively studied, the impact of obesity on the right heart remains less well characterized. We aimed to assess right atrial (RA) and right ventricular (RV) morphology, function, and myocardial deformation across obesity classes and their association with anthropometric and metabolic parameters. This cross-sectional study included 126 adults with overweight and obesity. Echocardiographic assessment comprised RA and RV dimensions, RV systolic function (TAPSE, FAC, and s'TDI), RV global longitudinal strain (RV GLS), and RA strain analysis, including reservoir (PALS) and contractile (PACS) function. Comparisons were performed according to obesity class, and correlations with adiposity and metabolic markers were analyzed. Subjects with class III obesity demonstrated significantly larger indexed RA short-axis dimensions than those with class I and II obesity (p=0.001), suggesting early RA remodeling. RV dimensions, FAC, TAPSE, RV GLS, and RV free-wall GLS did not differ significantly among obesity classes and showed no meaningful associations with anthropometric or metabolic variables. In contrast, PALS showed negative correlations with body mass index (r=-0.220, p=0.014), waist circumference (r=-0.174, p=0.053), and hip circumference (r=-0.182, p=0.045). PACS was positively associated with fasting insulin (r=0.216, p=0.016) and HOMA-IR (r=0.214, p=0.017). Impaired RA reservoir function appears to be an early manifestation of obesity-related cardiac involvement, whereas RV function and strain remain preserved. RA strain may serve as a sensitive marker of subclinical right heart dysfunction in obesity.