小児期の特発性肥大型心筋症の臨床的検討—電気生理，心内膜心筋生検および心電図変化と長期フォローアップ

Clinical investigation on childhood HCM:long term follow-up study with special reference to electro-physiology, histopathology by endomyocardial biopsy and ambulatory and exercise electrocardiography

　小児期の肥大型心筋症は近年の学童心電図検診の普及で発見される症例も増加しつつあるが，その病態・予後はいまだ不明の点が数多く残る。そこで本症のリスクファクターを探る目的で比較的長期間観察でき，種々の臨床，病理学的パラメータを検討できた小児10例を研究対象とした。発見動機は心雑音，発見時年齢は10〜15歳に多かったが，5歳以下で発見された2例は進行し，外科療法を余儀なくされた。胸痛で発見された1例は突然死をきたしており，有症状例はリスクが高いと思われた。発見時心電図は特有であり，経過中に著明に変化した例もあった。小児期の心尖部肥大型心筋症の診断は慎重であるべきである。フォローアップ心電図としてホルター心電図は不可欠である。病理組織学的重症度と臨床像は必ずしも平行しなかった。小児期本症は，heterogeneousかつmultifacetedであり画一的な治療予後は望まれず症例ごとのきめ細かな対応が求められる。

In order to determine the prognosis and risk factors of childhood HCM, we investigated clinical parameters, such as the age of onset, symptomas and signs related to HCM, dysrhythmias and ST-T and changes by Holter ECG and exercise ECG, electrophysiological study and histopathological study by endomyocardial biopsy.

Heart murmur was the commonest sign although only one patient revealed a significant left ventri-cular outflow tract gradient of more than 20 mmHg. The peak age of patients diagnosed as having HCM was 10 to 15 years. The major ECG manifestations of our series showed specific findings and in some cases ECG changed remarkably during the follow-up period. The diagnosis of apical hypertrophy should be made with cauton in childhood. Holter ECG seemed to be indispensable for the follow-up of childhood HCM because Holter ECG in our patients manifested such significant findings as ven-tricular premature contractions or couplets or ST depression.

The degree of clinical severity did not always correlate with the histopathological severity obtained by endomyocardial biopsy. As HCM in childhood is heterogeneous and multifaceted, there is no one therapy, and prognosis and proper treatment with close observation should be carried out in each individual case.