心エコー上粘液腫との鑑別が困難であった左房内血栓の1例

Left Atrial Thrombus Similar to Myxoma:A case study

　症例は75歳，男性．主訴はめまいと意識消失発作．1988年1月から歩行中めまいがあり，座り込んでいた．その後冠攣縮性狭心症，陳旧性心筋梗塞，徐脈性心房細動の診断を受けたが，1994年心不全にて入院中，痙攣後に一時意識を消失，てんかんと診断された．また，頭部CT上多発性脳梗塞の所見があり，経食道心エコー（TEE）上，左房内大動脈壁と接した部位に，径20×29mmの充実性腫瘤様エコーを認め，心原性脳塞栓症と診断された．腫瘤には茎が存在し，中心の高吸収域の部位と，周囲の内部エコー不均一で嚢胞様エコーを示す可動性の強い部分とに分かれていた．左房内血栓と左房粘液腫の両方を疑い，ワーファリンを投与したところ，4日後のTEEでは，表層の嚢胞様エコーを示す部分が消失し，1カ月後には中心の可動性に乏しい部分も消失した．その間，塞栓症状はなく，左房内血栓と診断した．左房内血栓と左房粘液腫の鑑別にTEEでの経過観察は有用と考えられた．

A 75-year old male who complained of faintness was admitted to our hospital. He had been previously diagnosed as having atrial fibrillation, vasospastic an-gina, old myocardial infarction, and aortic regurgita-tion. He was diagnosed as having epilepsy by electro-encephalography (EEG) and underwent transeso-phageal echocardiography (TEE) because brain CT showed multiple cerebral infarction. There was a spon-taneous contrast in the left atrium, and a mass attached to the left anterior wall adjacent to the aortic sinus. The mass was 20x29mm in size, and was composed of a bright lower part and a mobile upper part. The upper part seemed mottled and had areas of echolucency. The patient received warfarin and underwent serial TEE. The upper part of the mass disappeared 4 days later, and the whole mass disappeared one month later. The patient did not complain of any discomfort nor did he manifest any embolic sign during warfarin therapy. We conclude that warfarin therapy with serial TEE may be useful in discriminating left atrial thrombus and myxoma.