左心不全を呈した僧帽弁狭窄症の1例—その成因についての一考察

A case of mitral stenosis presenting left sided heart failure:One consideration about the genesis of left ventricular dysfunction in mitral stenosis

　リウマチ性僧帽弁狭窄症（MS）は，日常臨床にて数数遭遇する一般的な心疾患であるが，本症における左心機能低下の成因については意外にも詳細には明らかにされてはおらず，現在もなお議論の多いところである。一般に，左心不全を呈するMSでは，左室後壁基部を中心とする局所的変形，収縮異常が数々存在し，これにより左心機能低下をきたすことが報告されている。今回我我は，左心機能低下の主成因として，それらの変化に加え，同じくリウマチ性変化に基くと思われる広範な心筋障害もその一因として考えられたMS患者1例を経験した。今後，本症の左心機能障害を考察する上で示唆に富む症例と思われたので，若干の文献的考察を加え報告する。

A 46-year-old man with rheumatic mitral stenosis presenting left sided heart failure was described. Electrocardiogram showed atrial fibrillation with bradycardia and non-specific ST-T changes at all leads. Left atrium-Left ventricle diastolic pressuregradient was not so significant as could be responsible for the subjective symptoms. Left ventriculography revealed diffusely reduced contractility and severe deformities at postero-basal and antero-basal por-tions. Endomyocardial biopsy in right ventricle de-monstrated myocardial degeneration and interstitial fibrosis, which was considered non-specific myocar-dial damage. These findings indicate that not only abnormal left ventricular contraction due to "rigid mitral complex" but also diffuse myocardial damage might initiate left ventricular dysfunction in the present case, although it has been postulated that diffuse myocardial damage due to rheumatic myo-carditis seems unlikely to the cause of the left ventricular dysfunction in mitral stenosis. That is, the present case may suggest that diffuse myocardial damage probably caused by rheumatic myocarditis should be added to one of the "myocardial factors" in mitral stenosis and could be in part in the genesis of left ventricular dysfunction.