生前異型狭心症と診断され肺炎の合併のみられた1剖検例

An Autopsy Case of Variant Form of Angina Pectoris with Pneumonia

　症例は60歳，女性．約1年前より早朝の胸部圧迫感があり，入院後の冠動脈造影で右冠状動脈のみに攣縮所見がみられ，異型狭心症と診断された．Ca拮抗薬で安定していたが，肺炎で再入院，呼吸不全で死亡した．主要剖検所見としては，直接死因となった肺臓の重量は左650g，右1160gで組織学的に器質化肺炎，びまん性肺胞傷害と急性気管支炎が確認された．心臓は重量420gで新鮮な梗塞巣はみられず右心室の軽度拡張が認められた．組織学的には心内膜下に部分的に線維化巣がみられ，冠状動脈では内膜肥厚が右冠状動脈に左冠状動脈前下行枝・回旋枝と比較して著明にみられ，これらの内膜にはα平滑筋アクチン陽性の収縮型平滑筋細胞の増殖が認められた．冠動脈攣縮はこのα平滑筋アクチン陽性の収縮型平滑筋細胞の増殖を伴う内膜肥厚が基盤としてあるところにシェアストレスや血管支配神経刺激などが加わって惹起されると考えられる．

An autopsy case of a variant form of angina pectoris with pneumonia is reported. The patient was a 60-year-old female, who had been suffering from chest oppression. During coronary angiography, she suddenly experienced chest oppression, and vasospasm of her right coronary artery was confirmed. The diagnosis was variant form of angina pectoris and a calcium antagonist was effective. About four months later, she expired due to pneumonia. In the lungs, focal organiz-ing pneumonia in a late stage and diffuse alveolar damage in acute and organizing stages were demon-strated. Heart weight was 420 g and the right ventricle was dilated and associated with fatty infiltration. In the coronary artery thickened intima with α-smooth mus-cle actin positive cell proliferation was found. The intimal ratio, area of intima divided by that of lumen and intima, of segment 1, 2 and 3 was 74.5, 75.7 and 76.5 percent, respectively. On the basis of thickened intima with α-smooth muscle actin positive cell prolif-eration, shear stress or stimulation of the peripheral nerves might trigger coronary vasospasm.