原発性冠動脈解離の2例—その臨床像をめぐって

Two cases of primary artery dissection

　冠動脈造影にて診断した原発性冠動脈解離の2例を報告する。症例1は夜間および早朝安静時の胸痛が頻発する55歳男性。発作時に心電図上Ⅱ，Ⅲ，aV_FのST上昇を認めた。冠動脈造影では有意狭窄を認めず，右冠動脈Seg 3に索状陰影欠損を認めたため原発性冠動脈解離と診断。Ca^＋＋拮抗剤と亜硝酸剤投与にて胸痛発作は消失した。症例2はヘモグロビン異常症で治療中の27歳女性。入浴中に背部痛が出現し入院。心電図上V₂〜V₄のST上昇と異常Q波を認め，前壁心筋梗塞と診断。冠動脈造影にて左前下行枝Seg 6，Seg 9に90％の狭窄，さらにSeg 7に冠動脈解離を認めた。原発性冠動脈解離例は稀であり，冠攣縮症候群，急性心筋梗塞，ヘモグロビン異常症との関連が示唆された。

We experienced two cases of primary coronary artery dissection.

〔Case 1〕 55-year-old man had frequent episodes of chest oppression at early morning and midnight. During chest oppression, electrocardiogram showed transient ST-segment elevation in leads Ⅱ, Ⅲ, and aV_F. Then, he was diagnosed as having angina pec-toris. This diagnosis was based on the fact that he presented coronary spastic syndrome. Right coronary angiogram demonstrated an intimal frap and false lumen at segment 3, and primary coronary dissection was confirmed.

〔Case 2〕 A 27-year-old woman complained of back pain while taking a bath. Electrocardiogram showed ST-segment elevation and abnormal Q in leads V₂, V₃ and V₄. She was diagnosed as having acute an-terior wall myocardial infarction. Presence of coro-nary artery dissection at segment 6 was identified by left coronary angiogram.

Primary coronary artery dissection is clinically diagnosed by coronary angiogram very rarely. Only 27 such cases have been reported. It was speculated that, in case 1, vasospastic angina may be associated with primary coronary artery dissec-tion. Case 2 had primary coronary artery dissection at segment 6 of the left anterior descending artery. Thus, her clinical picture was similar to those of previously reported cases.