Evaluating the pure effect of weight on cardiac function in patients with cardiac syndrome X.

Abstract

Obese patients have more coronary artery disease (CAD) risk factors that may affect myocardial function. We aimed to assess the ability of echocardiography-derived conventional parameters, left atrial strain, and global longitudinal strain to detect early diastolic and systolic dysfunction in obese individuals with almost no CAD risk factors. We studied 100 participants with structurally normal hearts, ejection fractions above 50%, almost normal coronary arteries in coronary angiogram (syndrome X), and no cardiovascular risk factor except dyslipidemia. Participants were classified as normal-weight (BMI<25.0kg/m2 , n=28) and high-weight (BMI≥25.0kg/m2 , n=72). Conventional echocardiographic parameters and two-dimensional speckle tracking (2DSTE) were used to measure peak LA strain and global longitudinal strain to evaluate diastolic and systolic function, respectively. There was no significant difference in the standard and conventional echocardiographic parameters between the two groups. 2DSTE echocardiographic parameters of the longitudinal deformation of the LV myocardium were not significantly different within the two groups. However, there were significant differences between the subjects with normal-weight and high-weight in terms of LA strain (34.51±8.98% vs. 39.06±8.62%, p=.021). The normal-weight group had lower LA strain, in compression with the high-weight group. All echocardiographic parameters were in the normal range. In the present study we demonstrated that global longitudinal subendocardial deformations, for the evaluation of systolic function, and conventional echocardiographic parameters, for the evaluation of diastolic function, were not significantly different between normal- and high-weight groups. Although LA strain was higher among overweight patients, it was not above the normal range of diastolic dysfunction.