Effects of Isolated Obesity on Left and Right Ventricular Function: A Tissue Doppler and Strain Rate Imaging Study

Objective: To determine the subclinical effects of isolated obesity and its duration on cardiac function by using routine echocardiography and tissue Doppler myocardial strain rate. Methods: Forty-nine subjects were enrolled in this study; 29 with isolated obesity defined as a body mass index >= 30 kg/m2 with no other cardiovascular comorbidities, and 20 nonobese controls. All subjects underwent two-dimensional and Doppler echocardiography including tissue Doppler imaging and myocardial strain rate. Results: The average duration of obesity was 12.1 years (4-18 years). Abnormalities of left ventricular (LV) wall thickness, mass, diastolic function, and left atrial size were detected in obese individuals, despite having preserved ejection fractions. The LV global longitudinal peak strain rate was significantly lower in obese subjects compared to nonobese control subjects (1.07 +/- 0.14 vs. 1.38 +/- 0.12, P < 0.001). Using multivariate analysis, the duration of obesity (ss = -0.76, P < 0.001), body mass index (ss = -0.35, P = 0.023), and age (ss = -0.29, P = 0.009) were independent predictors of the decreased LV global longitudinal peak strain rate, while the duration of obesity (ss = -0.66, P < 0.001) and body mass index (ss = -0.28, P = 0.037) were independent predictors of the decreased right ventricular (RV) peak strain rate. Conclusion: The presence and the duration of obesity were associated with impairment of subclinical biventricular systolic and diastolic function. These findings have the potential to increase awareness of subclinical cardiac manifestations in patients with isolated obesity and influence their early management. (Echocardiography 2010;27:236-243).