低血圧症状が仰臥位でも生じたNeurally mediated syncopeの1例—入院後早期のhead-up tilt test施行困難の1例

Neurally Mediated Syncope with Severe Hypotension Even in the Supine Posture:How should we diagnose sucln cases?

　われわれは，著しい低血圧症状が仰臥位でも生じ，head-up tilt試験が病初期に施行できなかったneurally mediated syncopeの症例を経験したので報告する．症例は70歳，男性．主訴は失神発作．1996年7月16日，立位で失神発作を生じて精査目的入院．低血圧症状が仰臥位でも生じた．7月17日に脳血管，冠動脈，左室造影で有意所見なし．低血圧症状で，同日dopamine 10μg／分／m²を開始．3〜5μg／分／m²への減量で，仰臥位でも低血圧症状を繰り返した．norepinephrine, atropine sulfateの持続静注で改善傾向を認めた．7月28日にhead-up tilt試験で失神が生じ，neurally mediated syncopeと診断した．本症例は，8月中旬に中咽頭癌の合併が明らかとなった．薬物効果判定でbisoprolol 5mgとmidodrine8mgの併用が著効を示した．本症例の過大な症状（仰臥位での低血圧症状発現）と中咽頭癌との関連性には議論のあるところと考える．

We encountered a patient with NMS on whom wecould not perform a head-up tilt test during the onset period, because of severe hypotension even in the supine posture. A case of a 70-year-old male who developed syncope in the upright posture. He repeated syncope it the sitting posture and he was admitted to our hospital After admission, invasive cardiologic techniques offerer no suggestions as to the cause of this phenomenon Hypotension developed even in the supine position. We started therapy using dopamine 10μg/min/m². Diminish ing the dose to 3~5μg/min/m², the patient manifestedhypotension. Temporary pacing support was not ineffective for relieving the hypotension, and atropine sulfate and norepinephrine infusions were effective. Head-up tilt test was performed 13 days after admis-sion, and it was showen that syncope had developed. We diagnosed this case as neurally mediated syncope. One month after admission, we detected oropharyngeal can cer. In this case, the most effective therapy was biso prolol 5mg and midodrine 8mg p. o. We could not decide whether unusual symptom (severe hypotension it the supine position) was associated with oropharyngeM cancer or not.