肺切除後に発症した発作性心房細動に対してカテーテルアブレーションで根治できた1例

A Case of Paroxysmal Atrial Fibrillation Treated by Catheter Ablation after Lung Resection

要旨　患者は70歳，男性．2009年3月，肺腺癌に対して右上葉の肺葉切除を受けた2日日から発作性心房細動が出現．1年間の経過観察にても発作が頻発し治療目的で当院へ紹介．2010年7月に両側肺静脈拡大隔離術，三尖弁下大静脈間の線状焼灼を行い，以後45日間は発作なく経過したが，心房細動が再発し再度アブレーションを施行．左右肺静脈とも焼灼部位の伝導再開を認め拡大隔離を追加した．心房細動中に左肺静脈の隔離を行ったが細動は停止しなかった．右肺静脈の隔離を進めると心房頻拍へ移行し，隔離の完成とともに洞調律復帰を得た．以後発作は消失した．

　右肺上葉の切除を発症の契機としていたことから，心房細動は右肺静脈からの由来が考えやすく，アブレーション中の所見からも右肺静脈の関与が疑われた．

　肺切除後の心房細動発症は手術の合併症として少なからず報告されており，その原因は特定されていないが，本例はその機序を考えるうえで重要と考えられた．

　A 70-year-old male complained of palpitation due to paroxysmal atrial fibrillation(AF), that appeared 2 days after right upper lung cancer resection in March, 2009. Anti-arrhythmic agents being ineffective, we performed pulmonary vein isolation(PVI)in July,2010. AF relapsed on the 45th day after catheter ablation and we performed the second ablation in October, 2010. Bilateral additional ablation was needed, because of the re-connection between the left atrium and the pulmonary vein. We started PVI on the left side during AF, but AF did not terminate after the completion of PVI. However, during PVI on the right side, AF altered to atrial tachycardia and converted to sinus rhythm. After the second session, AF attack was free without anti-arrhythmic agents for one year.

　The AF in this case was related with the right pulmonary vein, because of the findings of catheter ablation. AF might be caused by inflammation or mechanical stress of the right pulmonary vein after right lung resection.

　In the previous reports, AF occurred in 8-42% patients after lung cancer resection and it was an important issue, because its occurrence was associated with longer hospital stay and higher cost and AF might herald other serious complications. The cause of post-operative AF was unclear, but this case suggested that pulmonary vein resection itself was a cause of AF.