巨大冠動脈痩の診断に経静脈的コントラストエコー図が有用であった1例

A Case of Giant Coronary Artery Fistula Diagnosed by Intravenous Contrast Echocardiography

　患者は72歳，男性．肥大型心筋症の診断で他院通院中であったが，今回胃癌に対する，術前精査目的のため当科に紹介された．経胸壁心エコー図で著明な心肥大と冠動脈中枢側の拡張と数珠状の管腔構造が認められ，巨大冠動脈瘤が疑われたが，末梢側の形病は不明瞭であった．そのため経静脈的コントラストエコー図を施行したところ，拡張期に左心室内に流入する血流が認められ，巨大冠動脈瘤および冠動脈痩と診断した．その後の冠動脈造影においても，左右冠動脈の著明な拡張と蛇行が認められ，両冠動脈ともに，左心室内への流入が確認された．冠動脈痩は一般に無症状であることが多いが，その開口部位や短絡量によっては心筋虚血や心不全が出現することがあり，的確な診断や注意深い経過観察が必要である．今回，コントラストエコー図を併用することで，非侵襲的に冠動脈造影とほぼ同等の診断能が得られたことは意義深いと考え報告した．

The patient was a 72-year-old male, under treatmentat another hospital for hypertrophic cardiomyopathy. He was referred to our clinic for detailed tests prior to an operation for cancer of the stomach. Transthoracic echocardiography revealed marked hypertrophy, dilata-tion and moniliform luminal structure of the proximal side of the coronary arteries, suggesting a giant-coro-nary aneurysm. As the configuration of the distal side was unclear, intravenous contrast echocardiography was conducted, which demonstrated coronary blood flow into the left ventricle at diastole. Consequently, a giant-coronary aneurysm and a coronary fistula were diagnosed. Coronary angiography showed marked dilatant and tortuous coronary arteries on both sides, through which blood flowed into the left ventricle. Although coronary artery fistula is generally asymptomatic, myocardial ischemia and heart failure may occur, depending on the site of the opening and the shunt volume. For this reason, it requires accurate diagnosis and follow-up. The use of contrast echocar-diography in the present case demonstrated a non-inva-sive diagnostic capability, which was as effective as coronary angiography.