一過性の壁肥厚を伴う特異な経過をたどった脚気心の1例

A Case of Beriberi Heart Disease that Showed a Peculiar Time Course of Recovery Accompanied with Transient Left Ventricular Hypertrophy

要旨

　患者は49歳，男性．アルコール多飲，偏食の生活歴があり，2週間前より下腿浮腫，息切れが出現し来院．胸部X線写真上心拡大，心エコー上右心系拡大，心膜液貯留を認め，心拍出量7.9l/min，肺動脈楔入圧28mmHgと高拍出性心不全を呈していた．以上の経過，検査所見から脚気心と診断し，ビタミンB₁投与を開始した．投与翌日には右心負荷は消失し肺動脈楔入圧は一旦正常化したが，2日後には再び上昇し，エコー上左室拡大，びまん性の壁運動低下，びまん性壁肥厚(14mm)を認めた．低拍出性心不全を呈していたため，利尿薬，カテコラミンの追加投与を行い，心不全は改善した．壁運動は正常化したが，壁肥厚は約2カ月間残存していた．一般に脚気心はビタミンB₁の投与で速やかに改善するが，本例のように末梢血管抵抗が急激に上昇し，低拍出性心不全へ移行することがある．しかし，脚気心の治療経過において一過性の壁肥厚が生じた報告は認められず，文献的考察を加えて報告する．

Summary

　We encountered a case of beriberi heart disease with low-output heart failure accompanied with transient left ventricular hypertrophy after the administration of thiamine. A 49-year-old male was admitted to our hospital with general edema on July 11th, 2002, He had been alcoholic and had existed on an unbalanced diet for about a year. Chest X-ray showed cardiomegaly and electrocardiogram showed low voltage in the limb leads. Echocardiography showed right ventricular(RV)dilatation and a small amount of pericardial effusion. He was diagnosed as having beriberi heart disease because of the typical clinical features and a low serum level of thiamine. After intravenous administration of thiamine, RV volume loading was immediately improved accompanied with a decrease of pulmonary capillary wedge pressure. However, this condition changed to low-output cardiac failure after two days. Echocardiography showed dilatation and diffuse hypokinesis of the left ventricle(LV) with severe hypertrophy. The low-output heart failure was improved immediately under the administration of diuretics and a low dose of catecholamine. However, the LV hypertrophy lasted for about two months. It was speculated that one reason for the low-output heart failure might have been transient LV hypertrophy. We reported this case of beriberi heart disease that showed a peculiar time course of recovery accompanied with the transient LV hypertrophy.