冠スパスムと関連した産褥後期急性心筋梗塞の1例

Acute Myocardial Infarction during Late Puerperium Related to Severe Vasospasm：a case report

要旨

　患者は30歳の健康女性．冠危険因子は喫煙だけである．第三子出産の6週間後，突然の胸痛を自覚し救急来院した．心電図上Ⅱ，Ⅲ，aV_FでST上昇を，心臓超音波検査で下壁壁運動低下を認めた．白血球数軽度増加以外は末梢血血球数，生化学検査，凝固系検査，自己免疫検査などは正常範囲内であった．緊急冠動脈造影にて右冠動脈に完全閉塞を認め，閉塞部に血栓様部分を認めたため血栓溶解療法を行い，造影遅延なく再開通を得た．3週間後，再造影にて右冠動脈に中等度狭窄を認め，エルゴノビンによる冠スパスム誘発にてtotal spasmが誘発された．以上より，厳しい冠スパスムと二次的な血栓に関連した急性心筋梗塞と診断した．産褥期の急性冠症候群は時折報告されるが，その発症機序の詳細はわからず，特に産褥後期における急性冠症候群の報告自体少ない．今回産褥後期の急性心筋梗塞で冠スパスムの誘発試験により発症機序を推定できたので報告した．

A 30-year-old woman during puerperium, who had given birth to her third child 42 days earlier, was admitted to hospital with acute chest pain. ST-segment elevation was recognized in Ⅱ, Ⅲ, and aV_F of the electrocardiogram on admission. Severe hypokinesis of the left ventricular inferior wall was also recognized by echocardiography. Suspecting her illness to be an acute coronary syndrome, we performed emergent coronary angiography. As a result, total occlusion was revealed in the right coronary artery. Nitrates were ineffective in relieving the patients condition. Recanalization with good coronary flow was gained by thrombolysis and her symptoms disappeared. The peak creatinin kinase was 2,903 mg/dl at 14 hours after onset. There was no abnormality found by the examination of coagulation activity or autoimmune activity. She made satisfactory progress, and three weeks later, coronary angiography was performed again. It revealed moderate stenosis in the right coronary artery, and total spasm was induced by ergonovine provocation. Accordingly, we diagnosed her illness as an acute case of myocardial infarction related to severe vasospasm and secondary thrombosis. We reported this late puerperal myocardial infarction as a rare case, and this report is thought to be noteworthy for consideration of the possible etiology of puerperal acute coronary syndrome.