心筋病変を認め，心室細動を来した成人型家族性房室ブロックの1例

Familial Atrioventricular Block of Adult Onset with Significant Myocardial Involvement and Ventricular Fibrillation

　患者は48歳，女性で，母親（詳細不明）と妹（房室ブロック）がペースメーカ植込みをうけている．I度房室ブロックと心室内伝導障害で通院していたが，失神発作で入院した際，刺激伝導系の広範な障害と左室収縮能の低下がみられ，右室心内膜心筋生検で心筋細胞の変性が認められた．ペースメーカを植込み，外来通院していたが，1年後，心室細動にて心肺停止となり，電気的除細動で救命された．本症例は左心機能低下，右室心筋生検での有意病変を伴い，心室細動を来した家族性房室ブロック（FAVB）の1例と考えられた．また，本例は，不整脈と伝導障害を主徴とする電気的障害型心筋症（ECD）の概念にもあてはまり，ECDとFAVBの関連性について，きわめて興味深い症例といえる．

A 48-year-old woman was admitted to our hospital on January 5, 2001, because of syncope. She had been diagnosed as I AV block at the age of thirty.Hermother (diagnosis was unknown) and her sister (AV block) had undergone pacemaker implantation.

In this hospitalization, diffuse conduction disturbance throughout most of the conduction system, and impaired left ventricular systolic function were observed. Myocardial degeneration was also detected in en-domyocardial biopsy from the right ventricle. (Coro-nary arteriography showed no stenotic lesions). The patient was treated with pacemaker implantation. About one year later, she suddenly lost consciousness owing to ventricular fibrillation, but was resuscitated.This case was diagnosed as familial atrioventricular block (FAVB) with impaired left ventricular function, significant histopathological abnormality of the ventri-cle, and ventricular fibrillation. It is also quite helpful for understanding the relation between an electric dis-turbance type of cardiomyopathy and FAVB.