126
releases adiponectin in response to left ventricular dysfunction, resulting in the ele-
vation of adiponectin plasma levels [ 73 ], which is a predictor of mortality in patients
with chronic heart failure [ 74 ].
It should be noted that the effect of weight loss on the reduction of epicardialadipose tissue is still controversial. For example, Wu et al. [ 75 ] examined the vol-
ume of epicardial adipose tissue (measured using CT scans) in two groups of over-
weight or obese patients. The first group underwent bariatric surgery, and the second
group participated in a 3-month aerobic exercise and low-calorie diet program.
Surprisingly, the epicardial adipose tissue was found to be unaffected by weight loss
in both groups of patients. A meta-analysis reported by Rabkin and Campbell [ 76 ]
suggested that significant epicardial adipose tissue reduction only occurred with
improved diet and bariatric surgery, but not with exercise.
5 Cardiac Mast Cells
Mast cells are connective tissue cells of hematopoietic origin. They originate from
CD34+ hematopoietic progenitor cells of the bone marrow and differentiate in sites of
connective tissue throughout the human body, including the heart. The internationally
accepted histological nomenclature, the Terminologia Histologica [ 38 ], distinguish
Fig. 8.6 A human heart visualized by scanning electron microscopy. A group of adipocytes from
the epicardium surrounded by a delicate network of reticular fibers. The lumen of a small coronary
vessel is observed (CV) (Orig. Magn. 372×)
I. Varga et al.