僧帽弁狭窄症の運動負荷心電図—心カテーテル検査・心血管造影所見との対比

Exercise Electrocardiograms in Mitral Stenosis Correlation with Cardiac Hemodynamics and Cineangiograms

　従来より，僧帽弁狭窄症で，不定の胸痛を訴える症例を時々経験する。また心電図でST segment低下を認め，運動負荷でそれがさらに増強することもしばしば経験されることである。しかし，一般に僧帽弁狭窄症の冠状動脈造影では，狭窄性病変が認められることは稀であり，これらの心電図変化がいわゆる冠状動脈硬化以外の他の要因によることは充分考えられる。本疾患の運動負荷によるST segment低下の程度は様々であるが，この心電図変化と僧帽弁狭窄症の病態との因果関係を見いだすため，血行動態や左室造影所見などとの対比検討を行ない，一つの見解を得たのでここに報告する。

Patients with mitral stenosis who complain of chest pain are sometimes observed. Twenty patients with mitral stenosis were exercised by the Master two-step test. Some of them showed significant S-T segment depression in the E. C. G. after exercise. All of them underwent cardiac catheterization and left ventriculography, and in thirteen patients selective coronary arteriography (C. A. G.) was performed. From the degree of the S-T segment depression the patients were divided into three groups (A : not depressed, B : <2 mm, C :≧2 mm). The correlation of the degree of the S-T segment depression with cardiac hemodynamics and cineangiograms was studied. The C. A. G. was performed in patients who could not be excluded from having stenosis of the coronary arteries from the clinical pictures, but it revealed no significant stenosis in any patients except in one case complicated with hypertension, diabetes mellitus and hyper-lipidemia. There was no correlation between the presence or extent of exercise-induced S-T depression and the resting pulmonary artery pressure, pulmonary capillary wedge pressure, and the mitral valvular pressure gradient. The left ventricular shapes in mitral stenosis were classified into types I~V according to the asynergy of the posterobasal area, the hypokinesis of the anterolateral wall and the basal bulge. We recognized that the degree of the S-T segment depression correlated markedly with the left ventricular shape (type I~V).The degree of the S-T segment depression tended to be proportional to the degree of the LV deformity.