心筋梗塞急性期に冠動脈に血栓塞栓を認め血栓溶解療法が不成功に終わった僧帽弁狭窄症の1例

A Case of Mitral Stenosis Associated with Acute Myocardial Infarction Demonstrated Coronary Thromboembolism which was unable to be Treated Successfully by Intracoronary Thrombolytic Therapy

　症例は一過性脳虚血発作の既往がある72歳の女性．1988年に僧帽弁狭窄症と心房細動を指摘され，心カテーテル検査を施行したが，冠動脈狭窄はなかった．以後，良好な抗凝固療法を施行していた．1994年2月，突然胸痛を生じ心電図上急性下壁梗塞症と診断された．発症4時間後に施行した冠動脈造影にて，右冠動脈末梢に血栓を示唆する完全閉塞所見を認めた．直ちに冠動脈内血栓溶解療法を行ったが，再疎通は得られなかった．発症17日後の冠動脈造影では閉塞部位は正常冠動脈像を呈していた．僧帽弁狭窄症に合併した急性心筋梗塞症に血栓溶解療法を施行した例は本例を含めて7例の報告がある，しかし，血栓溶解療法のみでは全例が急性期の再疎通が不成功であり，閉塞部位も心筋の灌流域が狭い部位が多く，全例慢性期に再疎通していた．本例は，僧帽弁狭窄症に合併した急性心筋梗塞症の治療は，保存的な治療を第一選択とすべきであることを示唆する症例と考えられた．

A 72-year-old woman with a history of transient cerebral ischemic attack was reported. She was diagnosed as having mitral stenosis with atrial fibrilla-tion but angiographically normal coronary arteries in 1988. Since then, she has had anticoagulant therapy to control symptoms. In February 1994, complaining of chest pain, she was diagnosed on ECG as having acute inferior myocardial infarction. Emergency coronary angiography 4 hours after onset showed total occlusion suggesting thromboembolism at the distal portion of the right coronary artery (#4AV). Intracoronary throm-bolysis using t-PA was performed immediately, but recanalization was not successful. The angiogram after 17 days revealed no stenosis at this occluded portion. Acute myocardial infarction associated with mitral stenosis despite the performance of intracoronary thrombolysis has been reported in seven cases including this case. In the acute phase, thrombolysis alone could not bring about recanalization, but in the chronic stage stenosis was not present. Moreover, in most of the cases, the obstructive portion of the coronary artery was distal and its perfusive myocardium was small. Our case suggested that acute myocardial infarction with mitral stenosis should be treated by conventional therapy rather than by thrombolysis.