特発性拘束型心筋症の2例—左室拡張期特性と予後との関連について

Two Cases of Idiopathic Restrictive Cardiomyopahy:Relationship between the left ventricular filling pattern and the prognosis

　臨床像の異なる拘束型心筋症（RCM）の2例を経験し，本症の拡張期特性と予後との関係について興味ある知見を得たので報告する．

　【症例1】33歳，女性．顔面と下腿の浮腫で発症した．初診時のパルスドプラ僧帽弁口血流速度波形は，拡張早期血流（E波）の減速時間（DT）が95msに短縮しており，高度の拘束型左室流入パターンを示した．心筋生検所見は，中等度の間質の線維化と心筋細胞の肥大を呈した．本例は，発症から5年後に心不全の増悪に加えて敗血症の合併で死亡した．

　【症例2】65歳，女性．1989年に労作時の呼吸困難で発症した．初診時のパルスドプラ僧帽弁口血流速度波形は，E波のDTが140msであり，DTの短縮が軽度にとどまった．心筋生検所見は，間質に軽度の線維化を呈したにとどまっていた．本例は，発症後8年の現時点でも心機能がNYHAI度に安定している．以上から，RCMでは，僧帽弁口血流速度波形での拘束型左室流入パターンから，心筋病理所見の重症度，さらには予後が予測し得ると推察される．

We report two cases of restrictive cardiomyopathy (RCM) with different clinical features. Diagnosis of RCM was made by echocardiography, the dip and pla-teau pattern of the ventricular diastolic pressure curve, and myocardial biopsy findings. Case 1 : A thirty-three -year-old female with RCM which had developed from facial and pretibial edema. Pulsed Doppler transmitral flow showed the short deceleration time of E wave (DT ; 95 ms: restricitive filling pattern). Right ventricular endomyocardial biopsy showed moderate interstitial fibrosis and mild hypertrophy of myocardial cells. Five years after the onset, the patient died of worsened heart failure and sepsis. Case 2 : A sixty-five-year old female with RMC which had developed from exertional dyspnea. Transmitral flow showed a mildly short DT of 110 ms. Endomyocardial biopsy showed modest inter-stitial fibrosis. Eight years after the onset, the patient is still stable in NYHA class I . Thus, we speculate that restrictive mitral inflow pattern is closely related not only with myocardial pathological severity but also with poor prognosis of RCM.