武井 康悦, 田中 信大, 宮城 学, 田村 忍, 高沢 謙二, 山科 章

Yasuyoshi TAKEI, Nobuhiro TANAKA, Manabu MIYAGI, Shinobu TAMURA, Kenji TAKAZAWA, Akira YAMASHINA

東京医科大学第二内科

The Second Department of Internal Medicine, Tokyo Medical University

キーワード : anticoagulation therapy, echocardiography (transesophageal), echocardiography (transthoracic), thrombosis

症例は77歳, 男性. 多発性脳硬塞, 発作性心房細動の検査の際に経胸壁心エコー図より左房内に可動性に富む球状の腫瘤像を認めた. 経食道心エコー図では心房中隔や左心耳より離れた左房後壁に付着した有茎性の腫瘤像を認めた. 僧帽弁疾患はなく, また検査時は洞調律であり左心耳入口部血流速も十分保たれていた. 緊急手術を勧めたが, 手術は施行せず低用量の抗凝固療法が選択された. 治療開始後は塞栓症の発症はなく約１ヵ月後の経胸壁, 経食道心エコー図では腫瘤像は完全に消失しており, この腫瘤は血栓と判断した. 本症例では軽度の左房拡大と発作性心房細動が血栓形成の要因と考えられたが, 血栓の消失過程においては低用量の抗凝固療法だけではなく心房細動の除去もその一役を担ったと考えられた. 血栓線溶の上で示唆的な経過をたどった症例と考えられ, 報告した.

A 77-year-old man with a left atrial mass was admitted to our institution. He had a history of paroxysmal atrial fibrillation and multiple cerebral infarctions. At time of admission, the electrocardiogram showed normal sinus rhythm; transthoracic echocardiography showed a mobile mass with a stalk in the left atrium but no significant mitral valve disorders; and transesophageal echocardiography showed a mass adhering to the left atrial posterior wall and spontaneous echo contrast in the left atrium and left atrial appendage, but the function of left atrial appendage was preserved. Although we recommended urgent surgery, the patient refused it and was therefore treated with low-dose anticoagulation therapy. He experienced no embolic episode or other symptoms during the follow-up period, and transthoracic and transesophageal echocardiography showed complete disappearance of the left atrial mass 1 month after his discharge from the hospital. From this course, we judged that the mass was a thrombus. This case taught us that maintenance of sinus rhythm in combination with anticoagulation therapy is essential for the theatment of thrombus.