Obesity is a chronic metabolic disorder associated with cardiovascular disease and increased morbidity and mortality. It is apparent that a variety of adaptations/alterations in cardiac structure and function occur as excessive adipose tissue accumulates.
Overt systolic and diastolic dysfunction has been described in obesity. New findings, indicating the occurrence of pre-clinical systolic and diastolic dysfunction, even in young obese patients, suggest that obese patients should be carefully monitored in order to detect incipient dysfunction.
Since traditional echocardiographic measurements of ventricular function, such as ejection fraction, fractional shortening and mitral inflow are load-dependent, the investigation of right and left ventricle subclinical dysfunction in obesity by sensitive newer echocardiographic techniques, such as tissue Doppler imaging, myocardial strain and strain rate looks like very promising. These techniques permit a quantitative assessment of both global and regional function and timing of myocardial events as well as the assessment of early changes in systolic and diastolic function.
Early detection of cardiovascular abnormalities is very important because the control of this process seems to be more effective during the initial stages of the disease.
The current study was conducted on 100 subjects were divided into two group without comorbidities, fifty subjects with BMI more than 30 representing the obese group, which were subdivided into two subgroups: group A which represents morbidly obese patients with BMI more than 35 & group B which represents mild obese patients with BMI more than 30 and fifty subjects with BMI less than 25 representing the control group referred to the echocardiographic lab at Benha University Hospital for echocardiographic
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assessment.
The candidates were subjected to the following:
1- History taking.
2- Clinical examination.
3- Laboratory examination.
4- Echocardiography (conventional echocardiography and tissue Doppler imaging) :with assessment of left ventricular dimensions, left ventricular systolic and diastolic function, left ventricular mass, left ventricular mass index. Tissue Doppler indices including systolic velocity, strain & strain rate were done for all patients.
This current study concluded that obese subjects had a significant increase in LVM and LVMI when compared with non-obese subjects.
It also concluded that healthy obese subjects exhibit alterations in LV structure and function manifested by eccentric LV remodeling, decreased global LV systolic function and also regional LV function and increased left atrial dimension.
Regional left ventricular systolic function showed significant reductions in systolic myocardial velocity and deformation properties among the obese subjects in the left ventricular selected segments in this study (longitudinal fibers) without reductions noted in strain rate of the posterior wall (circumferential fibers) as the reduction in longitudinal shortening in the early stage is compensated by an augmentation of circumferential shortening.
A highly significant direct relation was found in the present study between BMI versus left ventricular mass and left ventricular mass index, significant inverse relation between BMI and the peak systolic velocity of strain and strain rate.
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- So we concluded that TDI derived echocardiographic techniques used in this study may be new tools for early detection of subclinical cardiac functional and structural changes and to evaluate their natural history and the efficacy of therapeutic interventions over time. |
