神経疾患として加療中，特異な心電図変化を伴った高心拍出性心不全を発症し，確定診断に至った脚気の1例

A Case of Beriberi Developing High-output Heart Failure with the Distinctive Changes of the Electrocardiogram During the Clinical Course of Neuropathy

要旨　症例は61歳男性，11年前に胃癌で胃全摘の既往．その4年後より進行性の四肢のしびれと筋力低下を認め，慢性炎症性脱髄性多発神経炎として加療中であった．1カ月前から歩行困難や眼瞼下垂が再増悪したため入院，その際の心電図で無症候性にV_4-6誘導でST上昇を認めたが，採血上心筋逸脱酵素の上昇はなく，心エコーでも壁運動異常を認めなかったため経過を見ていた．2日後，急激に血圧が低下，呼吸困難を訴えたため胸部X線，心エコーを再検したところ，高心拍出性心不全を認めた．経過から脚気を疑って，直ちにビタミンB₁投与を開始したところ，数時間で循環動態は安定し，心不全も軽快した．またビタミンB₁の投与にて神経症状についても劇的に改善した．胃全摘後で神経症状を有する患者が，心疾患の合併を示唆する何らかの所見を呈した場合には，脚気の可能性を積極的に疑う必要があると考えた．

　A-61-year-old man, who had undergone total gastrectomy for gastric cancer eleven years ago, suffered from progressive numbness of the extremities and muscular weakness three years later. His case was followed-up as chronic inflammatory demyelinating polyneuropathy. One month ago, walking difficulty and eyelid ptosis worsened and he was admitted to our hospital. Electrocardiogram on admission showed asymptomatic ST elevation in V_4-6 leads. No enzymatic elevation was detected and normal contraction was confirmed with the echocardiogram. Two days later, his blood pressure suddenly decreased and he complained of dyspnea. Chest X-ray and echocardiogram revealed high-output heart failure. From his past clinical course, we suspected beriberi and immediately started the supplementation of vitamin B₁, and his hemodynamic and heart failure stabilized in a few hours. With the vitamin B₁ administration, his nervous system disorder was also improved. We diagnosed this case as beriberi containing neurological disorder. In the case of a patient with neurological disorder after gastrectomy, if the patient complains of any symptom suggesting the existence of heart disease, beriberi is to be suspected as a probable cause.