右室梗塞と肺血栓塞栓症を同時期に発症した1例

A Case of Acute Right Ventricular Infarction with Pulmonary Thromboembolism

要旨

　患者は64歳，女性．歩行中の息切れと胸背部痛を主訴に来院．心電図ではⅡ，Ⅲ，aV_F誘導と右側胸部誘導でST上昇を認め，心エコー検査では右室拡大と下壁の壁運動低下を認めたため急性右室梗塞の診断で緊急入院となった．頻脈傾向であり，血液ガス分析にて低酸素血症を認めたため，肺血栓塞栓症の合併が疑われた．肺血流シンチグラフィでは多区域に集積欠損を認め，早期に抗凝固療法を開始した．第5病日に実施した冠動脈造影では右冠動脈近位部に完全閉塞を認めた．経皮的冠動脈拡張術の施行により良好な拡張が得られ，右室枝が造影された．第16病日の肺血流シンチグラフィでは欠損範囲の縮小を認めた．心内血栓，下肢静脈血栓は確認できなかった．本症例は，急性右室梗塞と肺血栓塞栓症をほぼ同時期に発症した1例と考えられた．両疾患の病態生理は類似しているため，早期には肺血栓塞栓症の合併の診断が困難な例がある．右室梗塞の合併症として留意すべきと考えられた．

Summary

　A 64-year-old woman was admitted to our hospital with shortness of breath and chest pain. An electorocardiogram showed ST elevation in Ⅱ, Ⅲ, aV_F and V_3R, V_4R leads and echocardiography revealed dilatation of the right ventricule and inferior wall hypokinesis. A diagnosis of right ventricular infarction was made. The condition of tachycardia and hypoxemia in her blood gas analysis suggested that her condition was accompanied with pulmonary thromboembolism. The lung perfusion scanning showed multiple defects. Anticoagulation therapy was started immediately. On the fifth day, coronary angiography revealed that the right coronary artery(＃1)was totally occluded. PTCA was performed successfully. On the 16th day, lung perfusion scanning showed that the defect areas were clearly diminished. There was no finding of intra-cardiac or deep vein thrombus. This patient experienced acute right ventricular infarction and pulmonary thromboembolism at about the same time. Such complications may be more common than previously believed. However, early identification of this condition is difficult because both pathophysiologies are similar. The diagnosis should be performed carefully and, when it is made, prompt treatment and prevention of subsequent thromboric morbidity should be carried out.