Adiposity and ventricular dysfunction: a cross-sectional evaluation of the impact of overweight and obesity on left- and right-ventricular performance

Background and purpose: Obesity, defined as a body mass index (BMI) of 30 kg/m² or higher, increases cardiovascular risk through mechanisms such as hypertension and diabetes, and independently contributes to heart failure with preserved ejection fraction (EF). Tissue Doppler imaging (TDI) enables the detection of subtle dysfunctions in both left and right ventricular (RV) performance, highlighting the impact of obesity on cardiac function. This study aimed to assess the effect of increasing BMI on systolic and diastolic function of the left and right ventricles in obese adults. Methods: In this cross-sectional study, 142 adults with elevated BMI (≥25 kg/m²) attending the Department of Surgery, Faculty of Medicine, Tanta University, underwent a 12-lead surface electrocardiogram (ECG), conventional transthoracic echocardiography (TTE), and TDI assessment. Participants were categorized into four BMI groups: 25 to 30 kg/m² (n = 13), 30 to 35 kg/m² (n = 18), 35 to 40 kg/m² (n = 73), and >40 kg/m² (n = 38). Statistical analyses included one-way analysis of variance (ANOVA), Fisher exact test, Pearson correlation, and multivariable linear regression adjusted for age and sex. Results: Age and sex distributions were comparable across BMI groups, while BMI differences were highly significant (P < 0.001). Left ventricular EF (LVEF) demonstrated a borderline decline with increasing BMI (P = 0.049), but other LV parameters (left atrial [LA] diameter, LV systolic myocardial velocity [LV S’], tricuspid annular plane systolic excursion [TAPSE]) did not differ significantly (P > 0.05). In contrast, RV systolic function, as assessed by tricuspid S’, showed a marked and progressive reduction with higher BMI (P < 0.001). Multivariable regression confirmed that BMI was independently associated with lower tricuspid S’ (β = −0.222, P < 0.001). Pearson correlation and linear regression analyses further demonstrated a strong inverse relationship between BMI and tricuspid S’ (r ≈ −0.99, regression slope −0.14 cm/s per BMI unit, R² ≈ 0.98, P < 0.05). Conclusions: In this cross-sectional cohort, BMI was not significantly associated with LV systolic function but showed a strong, independent inverse relationship with RV systolic performance measured by TDI-derived tricuspid S’. These findings highlight the importance of targeted RV assessment in obese individuals, as increasing adiposity may contribute to early subclinical RV systolic impairment.