Evaluation of left ventricular circumferential contraction functions in obese patients

We aim to evaluate left ventricular (LV) function abnormalities, especially circumferential contraction functions, in obese patients.

Cases without coronary artery disease (CAD) were divided into two groups according to their body mass indexes (BMI).

Female predominance (P = 0.002), systolic blood pressure (BP) (P = 0.001), diastolic BP (P = 0.001), waist circumference (P < 0.001), left atrium (P < 0.001), LV end-diastolic diameter (P = 0.046), LV mass index (P = 0.001), and LV stroke volume (P = 0.016) were prominent in obese patients (BMI > or = 27). In obese patients, transmitral late velocity (P = 0.005) was prominent, and pulmonary vein antegrade diastolic velocity (PV-D) (P = 0.002) and mitral annular early diastolic pulsed-wave tissue Doppler imaging (pw-TDI) velocity (annular Ea) (P = 0.032) were lower. Transmitral late velocity was positively correlate with stroke volume (P = 0.029) and systolic BP (P < 0.001). Negatively correlation between PV-D and diastolic BP (P = 0.046) was found. And also, annular Ea velocity was negatively correlate with systolic BP (P = 0.017) and diastolic BP (P = 0.031). These findings may reflect LV longitudinal contraction abnormalities (LVLCA) and underlying mechanism that is responsible for LVLCA, may be volume and afterload alterations. However, LV circumferential contraction functions that evaluate by using pw-TDI, were not different among the groups.

In obese patients without CAD, it was clearly said that while LVLCA were evident, LV circumferential contraction abnormalities were not. This differentiation may be explained by subepicardial myocardial fiber that is responsible for LV circumferential contractions is supplied by coronary arteries, subendocardial myocardial fiber that is responsible for LV longitudinal contractions, is supplied by systemic circulation via LV cavity penetration.