右室拡張型心筋症の兄弟例

Case reports of right ventricular dilated cardiomyopathy in 2 male siblings

　元来．拡張型心筋症では左心系が侵されることが多く，その病変が右心系にまで及ぶこともあるが，右室拡張型心筋症と言う右心系の特定の疾患としての報告例は比較的少ない。ごく近年になってその報告例が増えはじめたものの，他の疾患群との混同が目につく。本文での2症例は同胞内発生であり，右室形態，その収縮性の低下とともに，心内膜心筋生検像より，右室拡張型心筋症と診断した兄弟例を経験したので報告する。

We report 2 male siblings (36 years old and 32 years old) who were recognized to be affected with right ventricular dilated cardiomyopathy. On the chest radiograms, cardio-thoratic ratio increased in the elder and was normal in the younger. The standard electrocardiograms indicated negative T waves in leads which reflect right ventricle in both cases. Holter's dynamic electrocardiograms in 24 hours showed no worthening arrhythmias except for occasional premature ventricular contractions in both cases. Two dimensional echocardiograms demon-strated more enlarged right ventricle and rather smallleft ventricle in these 2 cases, and this findings were more predominant in the elder. Both free right ventricular walls were denoted in diffuse hypokinetic movement with rather hypertrophic wall thickness, and dilated right atrium in the elder. The cardiac catheterization data of both cases were investigated as relative elevation of right atrial pressure with protruded "a" wave and also of right ventricular end-diastolic pressure, respectively, but these findings were predominant in the elder. Left ventricular end-diastolic pressures were in normal ranges. In the elder, cardic index decreased to 1.9l/min/m2, in the youner remained at 2.6l/min/m2. The contrast right ventriculogram of the elder indicated tricuspid regurgitation. In the histological studies of right ventricular endomyocardial biopsy specimens, myocardial cells illustrated irregular hypertrophies, disarraies, fatty infiltrations, and fibrous degenera-tions, respectively.

Hereditory factor was presumed in maternal line, that is, two male adults (an uncle and a cousin) died suddenly at their homes. But it was not clear that they have been suffered from some heart diseases.