Terasaki T, Takazakura E, Tsuji H, Terada Y, Makino H, Gabata T
Department of Internal Medicine, Kurobe Municipal Hospital, Toyama-ken, Japan.
Nihon Kyobu Shikkan Gakkai Zasshi. 1994 Feb;32(2):156-60.
A 74-year-old man was admitted to our hospital for work up of a shadow in the right middle lobe on chest X-ray film. He had hypertension, aortic regurgitation, and atrial fibrillation on admission. Bronchoscopy demonstrated total obstruction of the right B4 orifice, but the etiology of obstruction was unknown. He was discharged and followed up. The shadow in the middle lobe disappeared spontaneously and the cardiac silhouette was slightly smaller than that on the first admission. The shadow in the middle lobe reappeared again with the progression of cardiomegaly. Because hypertension became uncontrolled and pretibial edema developed, he was readmitted. Bronchoscopy showed the same findings as on the first admission. After treatment of heart failure for one month, bronchoscopy demonstrated partial patency of the right B4 orifice. As cardiomegaly improved, the shadow in the middle lobe diminished and then disappeared, and chest CT scan showed patency of the right B4. These findings suggest that congestive heart failure caused the atelectasis of the right middle lobe, so-called middle lobe syndrome. A possible mechanism of the right B4 obstruction is that the right B4 was compressed between the middle lobe artery and the dilated middle lobe vein due to heart failure.
一名74岁男性因胸部X线片显示右中叶有阴影而入院。入院时他患有高血压、主动脉瓣关闭不全和心房颤动。支气管镜检查显示右B4开口完全阻塞，但阻塞的病因不明。他出院后进行随访。中叶阴影自行消失，心脏轮廓比首次入院时略小。随着心脏扩大，中叶阴影再次出现。由于高血压控制不佳且出现胫前水肿，他再次入院。支气管镜检查结果与首次入院时相同。心力衰竭治疗一个月后，支气管镜检查显示右B4开口部分通畅。随着心脏扩大改善，中叶阴影缩小然后消失，胸部CT扫描显示右B4通畅。这些发现提示充血性心力衰竭导致了右中叶肺不张，即所谓的中叶综合征。右B4阻塞的一种可能机制是，由于心力衰竭，右B4被中叶动脉和扩张的中叶静脉挤压。
