Cardiac Abnormalities as a New Manifestation of Nonalcoholic Fatty Liver Disease: Echocardiographic and Tissue Doppler Imaging Assessment

Abstract

Nonalcoholic fatty liver disease (NAFLD) is linked to the metabolic syndrome. The aim of the present study is to determine the effect of the metabolic syndrome on left ventricular (LV) geometry and function using as a model patients with NAFLD. Thirty-eight patients with NAFLD, less than 55 years of age and with a normal exercise test, were compared with an age and sex-matched control group. Patients with diabetes mellitus, hypertension, and body mass index>40 were excluded. A complete echocardiographic study including tissue Doppler imaging (TDI) was performed. The following parameters were assessed by echo Doppler: peak velocities of early (E) and late (A) diastolic filling, E/A ratio, flow propagation velocity (Vp). Using TDI early diastolic velocity (E'), and systolic velocity (S') of mitral annulus were obtained. The patients with NAFLD had a significantly higher body mass index (31.4+/-5 vs. 26.4+/-4 kg/m, P=0.01), higher glucose (100.6+/-13 vs. 83.0+/-10 mg/dL, P=0.01), and triglyceride levels (126.5+/-44 vs. 206.5+/-67 mg/dL, P<0.001). Increased thickness of the intraventricular septum, posterior wall (11.03+/-2.2 vs. 8.9+/-2.9 mm, P=0.001; 8.5+/-1.7 vs. 9.7+/-2.3 mm, P=0.04), and larger LV mass and LV mass/height (160.7+/-58.7 vs.115.3+/-35.4 g, P=0.001 and 92.6+/-29.5 vs. 69.2+/-19.8 g/m, P=0.001, respectively) were found in NAFLD group. LV systolic function was similar in both groups. Patients with NAFLD had a lower E (73.6+/-11.0 vs. 86.4+/-20.0 cm/s, P<0.006) and E/A ratio (1.0+/-0.3 vs. 1.76+/-0.8 P<0.0001). Moreover, the Vp and the E' on TDI were significantly lower compared with the control group (49.0+/-9.7 vs. 74.7+/-18.4 cm/s, P<0.0001 and 10.3+/-2.0 vs. 13.8+/-1.7 cm/s, P<0.0001, respectively). On multivariate analysis the E' on TDI was the only independent parameter associated with NAFLD. In conclusion, patients with NAFLD in the absence of morbid obesity, hypertension, and diabetes have mildly altered LV geometry and early features of left ventricular diastolic dysfunction. Early diastolic velocity on TDI was found to be the only index that could identify the patients with NAFLD and metabolic syndrome.