The ventricular epicardial fat is related to the myocardial mass in normal, ischemic and hypertrophic hearts

Abstract

Background The purpose of the present study was to evaluate the extent of the ventricular epicardial fat and its relationship with the underlying myocardium, neither of which is still completely understood. Methods A total of 117 autoptic human hearts was subdivided into four groups: normals (N), ischemics (I), hypertrophics (H) and hypertrophic–ischemics (HI). In each heart, the ventricular myocardial and epicardial fat weights were measured. On the basis of these data, the epicardial fat percentage within the ventricles was calculated. Results The left, right and total ventricular fat weights were greater in H and HI than in N and I ( P<.05, P<.05, P<.01, respectively). No differences were detected in the epicardial fat weights in comparing H versus HI and N versus I. Moreover, the fat percentage in each ventricle did not vary between the four groups. However, if compared with the right ventricle, the left ventricle showed an epicardial fat percentage consistently lower ( P<.0001). In nonhypertrophied hearts (N and I), the body mass index and the total epicardial fat weight were correlated ( P<.05), whereas in hypertrophied hearts (H and HI), they were not. Conclusions A constant fat–muscle ratio exists in each ventricle, which is not influenced by ischemia or hypertrophy. Accordingly, during the hypertrophic process, the ventricular fat and the underlying myocardium show a parallel and correlated increase in their masses.