心エコー図によるDuchenne型筋ジストロフィーの心合併症の評価—人工呼吸器装着例と非装着例の比較

Evaluation of Cardiac Complications in Patients with Duchenne Muscular Dystrophy Using Echocardiography : A Comparison between Patients with and without Mechanical ventilation

　Duchenne型筋ジストロフィー（DMD）において，呼吸不全の管理のため人工呼吸器を装着している群と人工呼吸器の必要のない非装着群の左右心障害の程度を心エコー図にて比較検討した。対象は，装着群5名と非装着群14名で，年齢と機能障害度は装着群で有意に高値であった。右室径の拡大および心室中隔奇異性運動の有無から右心負荷の推定を行うと，両群でともに右心負荷の徴候は認められなかった。一方，左室局所壁運動異常の合併は両群で有意差を認めなかったが，左室収縮指標は人工呼吸器装着群で有意に低値であった。DMDの右心負荷は呼吸管理により予防可能であり，それ故左室障害の進行の予知や管理が重要である。

Two-dimensional echocardiography and Dop-pler echocardiography were performed in 19 patients with Duchenne muscular dystrophy forevaluating right ventricular overload and left ventricular function. Five of 19 patients were treat-ed with mechanical ventilation.

We defined right ventricular overload as right ventricular enlargement and the presence of para-doxical ventricular septal motion. The right ventricular dimensions in patients with mechanical ventilation were significantly larger than in patients without mechanical ventilation (p＜0.01) . All the patients with and without mechanical ventilation showed no significant right ventricular enlargement and none of them showed paradoxical ventricular septal motion. As for left ventricular function,, there were no significant differences in the incidence ofregional or diffuse wall motion abnormalities between two groups. However, the left ventricular fractional shortening was significantly lower in patients with mechaniccal ventilation than in patients without it (p＜0.05), and the incidence of mitral regurgitation was significantly higher in the former than in the latter (p＜0.01).

Our findings suggest that right ventricular func-tion is preserved even in patients with respiratory failure by appropriate respiratory treatment. There-fore, we should give attention to the progression of left ventricular dysfunction in long term prognosis.