Mambo N C, Silver M D, McLaughlin P R, Huckell V F, McEwan P M, Britt B A, Morch J E
Hum Pathol. 1980 Jul;11(4):381-8. doi: 10.1016/s0046-8177(80)80036-0.
Cardiomyopathy develops in some individuals who have a susceptibility to malignant hyperthermia. We studied right ventricular endomyocardial biopsy specimens from nine patients defined as having this disorder because of positive caffeine contracture tests on skeletal muscle biopsy specimens. Three patients had clinical evidence of cardiomyopathy and six did not. Light microscopy showed cytoplasmic contraction bands, perinuclear clearing, and a mild to moderate variation in myocyte and nuclear size. Ultrastructurally cytoplasmic contraction bands were associated with cardiac villi, myofiberlysis, and myofibrillolysis. These changes and occasional breaks in the sarcolemma were regarded as artefacts of the biopsy procedure. Megamitochondriosis with accompanying degenerative changes in the mitochondria were also seen and probably indicate increased cell metabolism; vacuolation of the cytoplasm was regarded as an "aging" phenomenon. Thus, the biopsy specimens were abnormal, but the changes were artefactual or nonspecific and were not unique to this group of patients. Biopsy did not provide a morphological explanation for abnormal cardiac function.
心肌病在一些对恶性高热易感的个体中发生。我们研究了9例患者的右心室心内膜活检标本，这些患者因骨骼肌活检标本咖啡因挛缩试验呈阳性而被定义为患有这种疾病。3例患者有心肌病的临床证据，6例没有。光镜下可见细胞质收缩带、核周透明，以及心肌细胞和细胞核大小的轻度至中度变化。超微结构上，细胞质收缩带与心绒毛、肌纤维溶解和肌原纤维溶解有关。这些变化以及偶尔的肌膜断裂被认为是活检过程中的人为现象。还可见巨大线粒体症以及伴随的线粒体退行性变化，这可能表明细胞代谢增加；细胞质空泡化被视为一种“老化”现象。因此，活检标本是异常的，但这些变化是人为的或非特异性的，并非该组患者所特有。活检并未为心脏功能异常提供形态学解释。
