18年間の心電図経過を追跡しえた進行性全身性硬化症に合併した不整脈源性右室異形成症の1例

Electrocardiographic Changes during 18 Years in a Patient with Arrhythmogenic Right Ventricular Dysplasia Accompanied with Progressive Systemic Sclerosis

　患者は47歳，女性．29歳より進行性全身性硬化症でprednisolone 5mg/日を内服中．30歳時，不完全右脚ブロック（QRS幅：0.10秒）であったが，36歳時よりε波が出現し，また，頻発する心室性期外収縮を認めた．その後，徐々にQRS幅が延長た，46歳時には0.14秒と延長を認めた．同時期に右室の拡大と右室全体および左室心尖部に限局した壁運動の低下がみられ，右室心内膜心筋生検で高度脂肪変性を確認した．長時間心電図では，散発する上室性期外収縮および心室性期外収縮（約1,000/日）を認めたが，持続性心室頻拍はない．心電図変化および心筋病理所見はARVDに典型的であり，18年間に及ぶ本症の心電図経過を観察した報告は稀で，本症の臨床経過を知るうえで貴重な症例と考えられた．

　A 47-year-old female was referred to our department for cardiac evaluation. She was diagnosed as having progressive systemic sclerosis at the age of 29. She has had frequent premature ventricular contractions from the age of 36.

　Her ECG had changed progressively from incomplete RBBB (QRS duration : 0.10 sec) at the age of 30 to complete RBBB (QRS duration : 0.14 sec) at the age of 46. Epsilon wave on V₁ lead and also negative T wave on V₁, V₂ lead have been noted since the age of 36. On ambulatory ECG monitoring, monofocal and frequent premature ventricular contractions without ventricular tachycardias was recognized. Echocardiography and ventriculography showed marked dilatation with diffuse hypokinesis of the right ventricle and akinesis of the left ventricular apex.

　Endomyocardial biopsy taken from the right ventricular posterior wall showed severe fibroadiposis with decreased myocardial cells, which was comparable with arrhythmogenic right ventricular dysplasia.

　We encountered a rare case of arrhythmogenic right ventricular dysplasia in which we were able to observe the ECG changes over 18 years.