福西 雅俊¹, 後藤 浩実¹, 佐藤 麻美¹, 田村 悦哉¹, 高野 良二¹, 縣 潤²

Masatoshi FUKUNISHI¹, Hiromi GOTOU¹, Asami SATOU¹, Etsuya TAMURA¹, Ryouji TAKANO¹, Jun AGATA²

¹社会福祉法人北海道社会事業協会帯広病院（帯広協会病院）臨床検査科, ²社会福祉法人北海道社会事業協会帯広病院（帯広協会病院）第二内科

¹Department of Clinical Laboratory, Social Welfare Corporation Hokkaido Social Work Association Obihiro Hospital (Obihiro Kyoukai Hospital), ²Second Department of Internal Medicine, Social Welfare Corporation Hokkaido Social Work Association Obihiro Hospital (Obihiro Kyoukai Hospital)

キーワード : coarctation of the aorta, hypertension, back vascular murmur, echocardiography

大動脈縮窄症は大動脈弓より遠位で動脈管接合部に狭窄を生じる先天性疾患である．心奇形を伴う複合型と動脈管が閉鎖し心奇形を合併しない単純型に大別され，成人例では薬物抵抗性の高血圧，上肢の高血圧と下肢血圧低下により発見されることが多い．我々は背部血管雑音を契機に発見された単純型大動脈縮窄症の成人例を経験したので報告する．症例は26歳，男性，感冒症状のため近医受診した際，高血圧と背部血管雑音，CTにて胸部大動脈拡張が指摘され精査となった．上肢血圧132/70mmHg左右差なく，背部脊椎左側に収縮期雑音を聴取した．心エコー図検査では，心臓に異常所見は認めなかったが，下行大動脈に33mmの拡張所見と内部に乱流が検出された．胸骨上窩からは，大動脈弓部の低形成と，その遠位部血管径が縮小し，その末端側の拡張が観察された．縮小部位に一致して狭窄血流を認め，連続波ドプラ法で求めた最大流速が3.4m/s，縮窄部前後の推定圧較差は46mmHgと計測された．腹部大動脈の流速が遅く，立ち上がりが緩徐で，拡張期にも末梢側へ流れる独特の波形を呈した．日頃より理学所見に注目し，大動脈走行の理解と描出を心掛けるべきであり，腹部大動脈血流波形に注意することで本疾患の存在が推測出来ると思われる．

Coarctation of the aorta is a congenital disease accompanied by distal aortic arch stenosis at a part of ductus arteriosus joint. Two main types of coarctation of the aorta are that with and that without heart malformation including patent ductus arteriosus. Coarctation of the aorta is usually diagnosed by drug resistant hypertension or upper limb hypertension, usually appearing in adults. We encountered an adult case of coarctation of the aorta with vascular murmur on the back and hypertension. The patient was a 26-year-old-man who had visited a clinic complaining of a common cold. Physical examination had detected abnormal vascular sound on his back. When the patient came to this institution for further examination, his upper limb blood pressure was 132/70 mm Hg without laterality, and vascular murmur was audible on the left side of his back. Plain CT indicated dilatation of the thoracic aorta when it was compared to the abdominal aorta. Although we detected no abnormality or source of abnormal sound in the heart, the descending aorta was dilated (33 mm) and the transthracic echocardiogram showed internal mosaic signals. Moreover, mild hypoplasia of the aortic arch, coarctation in the descending aorta, and post stenotic dilatation in the distal part of the coarctation were observed when viewed in the suprasternal approach. Maximal velocity and presumed pressure gradient at the coarctation were 3.4 m/s and 46 mm Hg, respectively, determined using the continuous wave Doppler method. The abdominal aortic flow pattern was highly unusual, including very slow flow and a slow rising pattern in the systolic phase and a prolonged flow pattern in the diastolic phase. We were able to detect coarctation of the aorta in this patient on the basis of physical findings obtained using transthracic echocardiography and by carefully depicting the aorta. We suggest that abdominal aortic flow pattern provides unique information that is important in identifying coarctation of the aorta.