ニフェカラント静注が無効でアミオダロン経管投与が奏効した致死性不整脈の1例

A Case of Near Fatal Arrhythmia which was treated not with Nifekalant,but with Amiodarone

要旨

　患者は45歳の男性で，入浴後より胸痛が出現したため救急車で来院した．心電図では，Ⅱ，Ⅲ，aV_F誘導で0.2mVのST部分の上昇が認められた．心筋梗塞と診断し，心臓カテーテル室へ搬送した．搬送途中で，意識レベルの低下および呼吸状態の悪化，脈拍の消失が認められたため，蘇生術を施行しながら搬送した．到着後，心電図で心室頻拍(以下VT)および心室細動(以下VF)が認められたため，直ちに直流除細動および人工呼吸器管理を行うとともに，リドカインの単回静注および持続静注を開始した．心臓カーテル検査中も頻回にVTおよびVFが出現するため，直流除細動を行いながらニフェカラントの単回静注および持続静注を開始した．冠動脈造影では右冠動脈の中枢部に完全閉塞が認められたため，胃管より粉砕したアミオダロン1,000mgの経管投与を行った．約30分後よりVTおよびVFは消失した．ニフェカラントとアミオダロンは，同じⅢ群抗不整脈薬であるが，作用機序や特性が異なる．難治性のVTおよびVFにおいて，ニフェカラントが無効である場合には，アミオダロンの経管投与を早急に考慮する必要があると考えられた．

A 45-year-old man was emergently admitted to our hospital because of severe chest oppression. An electrocardiogram demonstrated elevation of the ST segment in leads Ⅱ, Ⅲ, aV_F, and he was diagnosed as having acute myocardial infarction. On the way to the cardiac catheter laboratory his consciousness level abruptly decreased, and we performed cardiopulmonary resuscitation. After arriving at the catheter laboratory, ECG demonstrated ventricular tachycardia(VT)and ventricular fibrillation (VT). Although we performed defibrillation, intubation and an intravenous infusion of lidocaine, VT and VF occurred repeatedly. We performed cardiac catheterization with an intravenous infusion of nifekalant. Coronary angiography showed artery, and we performed an intervention with stents. Although revascularization was obtained, the incidence of VT and VF failed to decrease. We administered crashed amiodarone(1,000mg)through a stomach tube, and the near fatal arrhythmia vanished after 30 minutes. Nifekalant and amiodarone are Vaughan Williams class III antiarrhythmic drugs, but differ in their action and characteristics. In a case of near fatal arrhythmia which is intractable and resistant to nifekalant, it is necessary to administer amiodarone immediately through a stomach tube.