森本 紳一郎

Serial endomyocardial biopsy findings were analyzed in ten cases with acute myocarditis of possible viral origin. The histopathologic findings were analyzed at the acute (0-10 days after the onset), subacute (11-21 days), and convalescent stages (22-167 days). The incidence and severity of various cardiac myocyte and interstitial changes were compared at each stage of the disease. The time-course changes of the histopathologic findings in acute myocarditis were as follows. At the acute stage, we observed: (1) interstitial cell infiltration composed of fibroblasts, macrophages, and lymphocytes, (2) fragmentation of the muscle bundles, (3) myocytolytic changes, (4) swelling and scarcity of the cytoplasm and swelling of nuclei, (5) variation in size of the myocytes, (6) disarrangement of the muscle bundles, (7) interstitial edema, (8) increased glycogen deposition in the myocytes, (9) abnormal branching of the myocytes, and (10) interstitial fibrosis. At the convalescent stage, most of the above findings could still be seen except for myocytolytic changes, swelling of myocytes, and interstitial edema. At the subacute and convalescent stages, an increase in abnormal branching and in double nuclei in the myocytes and nuclear degeneration became observable. A further control study comparing the changes at the convalescent stage of myocarditis and the myocardial changes in cases with chronic right ventricular overload in 58 cases revealed that in the former fragmentation of the muscle bundles, abnormal branching, size variation, glycogen deposition, and large mononuclear cell infiltrations were significantly more frequent. Ultrastructural observation of the myocytes revealed that they have a great potentiality for regeneration myocytes showing severe myocytolytic changes may recover to regain an architecture of almost normal appearance. © 1985 Springer-Verlag.

"錯綜配列を伴う奇妙な心筋肥大:bizarrezarre myocardial hypertrophy with disorganization(BMHD)"が,肥大型心筋症(hypertrophic cardiomyopathy:HCM)に特異的であり,HCMの診断要素となるか否かを決定するため,成人の慢性右室負荷をきたす疾患72例の右心室心内膜心筋生検像の検討を行った.その結果,心筋の配列の乱れは81%の症例に高率に認められたが,BMHDは2.8%にすぎず,対照として同時に検索したHCM50例では,心筋の配列の乱れは92%例に,BMHDは66%例に認められ,BMHDのsensitivityは66%,specificityは97%,predictive accuracyは94%と算出され,BMHDをHCMの診断要素となし得ることが明らかにされた.さらに慢性右室負荷心の心筋細胞横径と右室圧との関係についても検討した結果,右室に圧負荷をきたす疾患群では,心筋細胞平均横径と右室圧との間に正の相関関係が認められ,心筋細胞の肥大は心室内圧と密接な関係が存在することが推測された.