松田 成人¹, 山口 高広¹, 竹内 元康², 南森 秀幸², 河村 晃弘², 川野 成夫², 林 英宰²

Naruto MATSUDA¹, Takahiro YAMAGUCHI¹, Motoyasu TAKEUCHI², Hideyuki NANMORI², Akihiro KAWAMURA², Shigeo KAWANO², Young-jae LIM²

¹河内総合病院心臓血管外科, ²河内総合病院循環器内科

¹Department of Cardiovascular Surgery, Kawachi General Hospital, ²Department of Cardiology, Kawachi General Hospital

キーワード : valve aneurysm, infective endocarditis, transesophageal echocardiography

弁膜瘤は比較的まれな疾患であり，その多くは感染性心内膜炎に続発することが知られている．症例は82歳，女性．慢性心不全の急性増悪にて来院した．発熱なく，血液検査では炎症反応を認めなかった．経胸壁心エコー図検査では僧帽弁前尖弁腹に約2.5 cm大の輪状構造物が認められ，カラードプラ法にて高度僧帽弁逆流が認められた．経食道心エコー図検査にて僧帽弁前尖の一部に欠損を有するドーム状エコー像を認めた．穿孔性僧帽弁膜瘤と診断し，僧帽弁置換術を施行した．切除標本は陳旧性心内膜炎の病理所見であり，弁膜瘤の原因として不顕性感染性心内膜炎が示唆された.

A rare case of ruptured mitral valve aneurysm associated with concealed infective endocarditis was accurately diagnosed by transesophageal echocardiography. An 82-year-old woman with progressive dyspnea was referred to our hospital. She was not febrile and there was no significant sign of inflammation. Transthoracic echocardiography showed a saccular lesion in the anterior leaflet of the mitral valve and severe mitral regurgitation. Transesophageal echocardiography clearly demonstrated a ruptured mitral valve aneurysm measuring, 25×20 mm. Mitral valve replacement was performed. Microscopic study of the resected specimen revealed marked degeneration with infiltration of inflammatory cells, suggesting that the mitral valve aneurysm was caused by concealed infective endocarditis.