Adipose tissue in and around the heart. structural and functional insights from cardiac magnetic resonance

Cardiac adipose tissue is normally present in the epicardium, but a variable amount can also be present in the myocardium, particularly in the subepicardial regions of the right ventricular anterolateral and apical regions. Pathological adipose tissue changes may occur in both ischemic (previous myocardial infarction) and nonischemic (previous myocarditis, arrhythmogenic cardiomyopathy, lipomatous hypertrophy of the interatrial septum, cardiac lipomas and liposarcomas) conditions, with or without extensive replacement-type myocardial fibrosis. Cardiac magnetic resonance is the gold standard imaging technique to characterize myocardial tissue changes and to distinguish between physiological and pathological cardiac fat deposits. In this review, we present the most common conditions presenting with myocardial fatty infiltration or with fatty replacement and the best magnetic resonance sequences to detect them, providing a comparison with histological findings and discussing their clinical significance.