Assessment of abnormal LV myocardial deformation properties in obese patients by 2D based strain and strain rate imaging

Abstract

Background: Obesity predisposes to left ventricular dysfunction and heart failure, early detection of associated subclinical cardiac changes has important diagnostic and prognostic values. 2D strain and strain rate allow detection of subtle abnormalities of global and regional left ventricular systolic and diastolic functions. The study aimed to assess the effect of obesity on LV function by 2D strain and strain rate. Methods and results: 30 obese patients (31.7 ± 6.7 years) without apparent cardiovascular disease were enrolled and fifteen sex and age-matched non-obese healthy individuals were recruited as control group, all patients and controls underwent assessment by complete conventional echo and 2D based strain and strain rate (longitudinal, radial and circumferential). Conventional echo demonstrated that obese patients had increased LV dimension (P 0.04), LA dimension (P 0.01) and left ventricular wall thickness, and impairment of diastolic function (E/A 0.98 ± 0.2 vs 1.4 ± 0.3 P 0.002) while no affection of systolic function could be detected. By deformation imaging, there was a reduction in circumferential strain (−17.8 ± 3.4 vs −20.7 ± 2.1 P 0.004) and longitudinal strain (apical 4 view −19.4 ± 2.6 vs −21.4 ± 2.6 P 0.02, apical 3 view −17.5 ± 3.7 vs −20.9 ± 3.8 P 0.01). Similarly systolic strain rate (SRsys) and early diastolic SR (SRe) reduced significantly in longitudinal and circumferential directions. On the contrary radial S and SR did not show any significant changes between both groups and did not correlate with the degree of obesity. Conclusions: Although EF was not different between obese patients and controls, LV longitudinal and circumferential strain and strain rate by 2D speckle tracking were lower in the obese group.

Keywords

• Obesity
• Left ventricular function
• Strain
• Strain rate
• Echocardiography