Severe Obesity Impairs Systolic and Diastolic Heart Function – The Significance of Pulsed Tissue Doppler, Strain, and Strain Rate Parameters

Abstract

We assessed the impact of morbid obesity on systolic and diastolic heart function in severely obese, but otherwise healthy subjects and age-matched controls. Overall, 27 obese patients: 19 female (F) and 8 male (M) mean age 37±9, mean body mass index (BMI) 46±6 and 27 control subjects: mean age 36±10, mean BMI 23±3 were examined by transthoracic echocardiography, including tissue Doppler echocardiographic (TDE) assessment and speckle tracking echocardiography to measure left ventricular longitudinal, circumferential, and radial strain (S) and strain rate (SR) during systolic and early diastolic phase. Obese patients presented with enlargement of both ventricles and the left atrium, and thicker left ventricular wall. Although left ventricular ejection fraction (EF) as well as amplitude of tricuspid annulus plane systolic excursion (TAPSE) was similar, the amplitude of mitral annulus plane systolic excursion (MAPSE) and ventricular systolic and early diastolic velocities measured by TDE were significantly lower for both ventricles in the obese group. (RV S' 13±3cm/sec vs. 15±2cm/sec, P=0.0057; LV S' lat 8.5±1.6cm/sec vs. 12.1±2.8, P<0.0001, E' lat: 12.4±2.9 vs. 16.4±3.5cm/sec for left ventricular and E' 12±3cm/sec vs. 18±4 for right ventricular velocities, P<0.0001). Among the deformation parameters, systolic and diastolic circumferential and systolic radial strain and SR were decreased in the obese subjects, whereas longitudinal strain did not differ significantly. TDE parameters documented reduced systolic and diastolic function of both ventricles in obese patients. 2-dimensional speckle tracking analysis revealed that circumferential and radial but not longitudinal strain and SR were impaired in the obese group.