早川 勇樹¹, 安 隆則², 藤井 幹久², 小塚 裕之¹, 梅澤 志寿子¹, 笠井 典子¹, 湯舟 憲雄¹, 久保 典史², 鮨玖陸 宗靖²

Yûki HAYAKAWA¹, Takanori YASU², Mikihisa FUJII², Hiroyuki KOTSUKA¹, Shizuko UMEZAWA¹, Noriko KASAI¹, Norio YUBUNE¹, Norifumi KUBO², Muneyasu SAITO²

¹自治医科大学附属大宮医療センター生理機能検査, ²自治医科大学附属大宮医療センター循環器科

¹Unit of Clinical Physiology, Omiya Medical Center, Jichi Medical School, ²Cardiovascular Division, Omiya Medical Center, Jichi Medical School

キーワード : echocardiography, hypertrophic obstructive cardiomyopathy, percutaneous transluminal septal myocardial ablation

Percutaneous transluminal septal myocardial ablation was introduced as a method for treating symptomatic hypertrophic obstructive cardiomyopathy. Here we explore serial changes in pressure gradient in the left ventricular outflow tract, septal myocardial thickness, and wall motion in patients with hypertrophic obstructive cardiomyopathy before and after percutaneous transluminal septal myocardial ablation was carried out. The subjects consisted of three consecutive patients with symptomatic hypertrophic obstructive cardiomyopathy who underwent percutaneous transluminal septal myocardial ablation. All three patients had pressure gradients greater than 120 mmHg in the left ventricular outflow tract as demonstrated by continuous Doppler echocardiography before ablation. Doppler echocardiography was repeated immediately after and 2, 14, 180, and 540 days after ablation. Pressure gradient in the left ventricular outflow tract decreased abruptly in two patients after ablation, although they showed a transient increase in pressure gradient as a result of myocardial edema two days later. The other patient showed no significant decrease in pressure gradient immediately after percutaneous transluminal septal myocardial ablation but did show a significant decrease 14 days later. Echocardiography 14 days after ablation demonstrated akinesis and wall thinning of the basal septum with high subendocardial echo-intensity. Two patients showed further reduction in the pressure gradient in the left ventricular outflow tract 180 days after the procedure. Symptomatic improvement paralleled a reduction in the pressure gradient in the left ventricular outflow tract. Follow-up study by Doppler echocardiography is highly recommended after percutaneous transluminal septal myocardial ablation, even after a completely successful procedure, because dynamic changes in the left ventricular outflow tract pressure gradient can result from several different cardiac and noncardiac factors.