Abstract 1883: Obesity Impairs Left Ventricular Circumferential but not Longitudinal Systolic Function in Hypertensive Subjects with Preserved Ejection Fraction
Background - Isolated obesity has been shown to negatively affect cardiac function in otherwise healthy subjects by means of alterations in left ventricular (LV) structure and morphology as well as either sub-clinical or clinical systo-diastolic mechanics. In the present study, we sought to investigate the influence of obesity on LV systolic function in hypertensive subjects with preserved ejection fraction (EF).
Methods - Studies were performed in 38 normal-weight (body mass index [BMI] 22.3±0.29 kg/m2), 50 overweight (BMI 27.1±0.20 kg/m2), and 24 obese (BMI 32.2±0.31 kg/m2) age- and sex-matched hypertensive subjects with mean ejection fraction (EF) 63±0.85%. All 112 subjects underwent standard echocardiographic examination with the assessment of midwall fractional shortening (mFS), stress-corrected mFS (scmFS), M-mode derived left atrio-ventricular plane displacement (AVPD) and pulsed tissue Doppler-derived peak mitral annular systolic velocity (Sm).
Results - Data are shown in the Table⇓. There were no significant intergroup differences in anti-hypertensive treatments, LV diameters, septal and posterior wall thicknesses, relative wall thickness and transmitral inflow diastolic velocity patterns. mFS and scmFS were significantly lower in obese subjects as compared to overweight and normal-weight subjects (p<0.05 vs normal-weight). In contrast, AVPD and Sm did not differ between the 3 subjects groups.
Conclusions - In hypertensive subjects with preserved EF, obesity impairs circumferential systolic function without affecting longitudinal systolic function. It is likely that the deterioration of midwall mechanics may constitute the first step in the progression toward LV systolic dysfunction in obese hypertensive subjects.