Basso Cristina, Thiene Gaetano
Institute of Pathological Anatomy, University of Padua Medical School, Padua 35121, Italy.
Cardiovasc Pathol. 2005 Jan-Feb;14(1):37-41. doi: 10.1016/j.carpath.2004.12.001.
Whether fatty infiltration of the right ventricle has to be considered "per se" a sufficient morphologic hallmark of arrhythmogenic right ventricular cardiomyopathy (ARVC) is still a source of controversy; ARVC should be kept distinct from both fatty infiltration of the right ventricle and adipositas cordis. In fact, it is well known that a certain amount of intramyocardial fat is present in the right ventricular antero-lateral and apical regions even in the normal heart and that the epicardial fat increases with increasing body weight. However, both the fibro-fatty and fatty variants of ARVC show, besides fatty replacement of the right ventricular myocardium, degenerative changes of the myocytes and interstitial fibrosis, with or without extensive replacement-type fibrosis. The need to adopt strict diagnostic criteria is warranted not only in the clinical setting but also in the forensic and general pathology arena. When dealing with a case of sudden death, in which the only morphologic finding consists of an increased amount of epicardial or intramyocardial fat, a more convincing arrhythmogenic source such as myocardial inflammatory infiltrates, fibrosis, anomalous pathways, and ion channel disease should always be searched for, in order to avoid an over-diagnosis of ARVC cases.
右心室脂肪浸润本身是否应被视为致心律失常性右心室心肌病（ARVC）的充分形态学标志仍存在争议；ARVC应与右心室脂肪浸润和心脏脂肪过多症区分开来。事实上，众所周知，即使在正常心脏中，右心室前外侧和心尖区域也存在一定量的心肌内脂肪，并且心包脂肪会随着体重增加而增加。然而，ARVC的纤维脂肪型和脂肪型除了右心室心肌被脂肪替代外，还表现出心肌细胞的退行性改变和间质纤维化，伴有或不伴有广泛的替代型纤维化。不仅在临床环境中，而且在法医和普通病理学领域，都有必要采用严格的诊断标准。在处理猝死病例时，若唯一的形态学发现是心包或心肌内脂肪量增加，则应始终寻找更具说服力的致心律失常来源，如心肌炎性浸润、纤维化、异常通路和离子通道疾病，以避免对ARVC病例的过度诊断。
