20年間観察した不整脈源性右室心筋症の1例—Fontaineの新しい分類を参照して

A Case of Arrhythmogenic Right Ventricular Cardiomyopathy followed up for 20 Yearswith referenc to the new classification of ARVC by Fontaine G et al.

　原因不明の右室拡張と収縮機能障害の女性例を20年問観察した．事務仕事をしていたが，28歳より労作時の息切れを生じた．30歳より右心不全症候を生じ3年間に5回の入院を繰り返した．胸部X線の心胸郭比拡大（59％から74％），心電図に多源性心室性不整脈とε波，遅延電位をみた．心臓超音波，心室造影検査，磁気共鳴画像により右室の著しい拡大，壁菲薄化を認めた．生検で心筋細胞の肥大や脱落，間質の脂肪浸潤と線維化をみた．心不全の増悪によりNYHA心機能分類IV度となった．Fontaineらにより新しく提唱された不整脈源性右室心筋症（ARVC）と診断した．左室拡張と収縮機能障害を伴うことから，亜分類として純型の両室異形成とするのが妥当と結論した．従来，不整脈源性右室異形成（ARVD）と呼ばれた疾患には様々な病態が含まれ混乱がみられた．新しい分類を参照し，本例の病態について論じた．

A 33-year-old woman with arrhythmogenic right ventricular cardiomyopathy followed up for 20 years was reported. She was found to have marked car- diomegaly in chest x-ray at age 13, though she did not have any manifestation of it until the age of 28, when she started to have dyspnea on exertion. At the age of 30, she developed symptoms of right ventricular failure and was admitted to the hospital repeatedly for its management. EKG recordings revealed multifocal ventricular arrhythmia with left bundle branch block pattern and epsilon waves which revealed a risk factor of severe ventricular arrhythmia. There was also late potential in signal-averaged EKG. The echocardiogram, ventriculography and magnetic resonance imaging showed right ventricular dilatation and thinning of the ventricular wall with poor left ventricular contraction. Myocardial biopsy showed hypertrophy and attenuation of myocells, interstitial infiltration of fat and fibrosis. Worsening of the right ventricular failure reached the NYHA class IV. We discussed the diagnostic problems in patients with ARVC, with reference to the new classification of ARVC by Fontaine G et al.