新田 政男¹, 高橋 涼子¹, 佐藤 明¹, 土肥 まゆみ¹, 足立 博正¹, 尾林 徹¹, 丹羽 明博¹, 高元 俊彦²

Masao NITTA¹, Ryoko TAKAHASHI¹, Akira SATO¹, Mayumi DOI¹, Hiromasa ADACHI¹, Toru OBAYASHI¹, Akihiro NIWA¹, Toshihiko TAKAMOTO²

¹武蔵野赤十字病院循環器内科, ²佐々木研究所付属杏雲堂病院循環器内科

¹Department of Internal Medicine, Musashino Red Cross Hospital, ²Department of Internal Medicine, Kyoundo Hospital

キーワード : Left atrial appendage thrombus, Mitral valve stenosis , Pulmonary venous flow velocity , Smokelike echoes

We used transesophageal echocardiography to study the clinical and pathologic features of smokelike echoes and left atrial appendage (LAA) thrombi in occasions of mitral stenosis (MS), both with and without atrial fibrillation (Af), and lone atrial fibrillation without rheumatic lesions. Forty-two patients had MS, and 77 had lone Af; mean age in the two groups was 57 years and 66 years, respectively. In MS patients with Af, smokelike echoes were observed in 26(84%) cases, and in 11(42%) cases with thrombi. In MS with normal sinus rhythm, smokelike echo was observed in only 1(9%) case. In the lone Af group, smokelike echoes were observed in 18(23%) cases, and only 2(3%) cases had thrombi in LAA. None of these thrombi or smokelike echoes were demonstrated by transthoracic echocardiography , however. The dimension and cross sectional areas in cases of LA and LAA, blood flow velocity in cases of LAA and PV, and LVEF and LV inflow blood velocity in the groups with and without smokelike echoes were compared. We found much larger LA volumes and LAA areas, slower blood flow velocities in LAA and PV, lower LVEF, and slower velocities of LV inflow in the group with smokelike echoes than in the group without these echoes. We thus conclude that stagnation of intra-atrial blood may play a major role in thrombus formation, and that transesophageal echocardiography detected both smokelike echoes and thrombi in cases with LA and LAA with great efficacy. Anticoagulation therapy is thus strongly recommended in cases of MS and atrial fibrillation.