発作性心房細動への直流通電除細動に対する塩酸アプリンジンの効果

The Usefulness of Aprindine for the Defibrillation of Paroxysmal Atrial Fibrillation Resistant to DC Shock

　直流通電（DC）除細動に抵抗性を示す発作性心房細動（Paf）に対し，塩酸アプリンジン（Ap）100mgを前投与し，直後に再度DC除細動を試みることで同剤の有効性を検討した．対象はDC除細動が無効な9例（僧帽弁膜症；2例，陳旧性心筋梗塞；2例，高血圧性心疾患；2例，肥大型心筋症；1例，基礎疾患なし；2例）である．対象例の左房径は38〜59（49±8）mm，左室駆出率26〜79（58±8）％と，正常から低下例まで様々であった．Ap投与後DCにより9例中8例で除細動に成功し，再発も認めなかった．DC後に心拍数は低下しQT問隔の有意な延長を認めたが（p＜0.01），Ap投与前後で心電図上有意なパラメーターの変化はなかった．血行動態の変化は心機能低下例も含め認められなかった．DC除細動に抵抗性を示すPafに対しApの前投与は有効であり，血行動態の悪化もなく，心機能低下例にも安全に使用できた．本剤は難治性Pafに対し投与を試みる価値があるものと考えられた．

Defibrillation by direct current (DC) shock applied for paroxysmal atrial fibrillation (Paf) has not been observed in all patients. We tried a new method for the therapy in Paf resistant to DC shock, by applying DC shock again immediately after intravenous injection of aprindine. Subjects were 9 patients with Palwho had failed to recover sinus rhythm by antiarrhythmic drug. and by the application of DC shock. Ages ranged from 48 to 83 years 7 had underling heart disease (2 patients with mitral valve disease, 2 with OMI 2 with hyperten-sion and 1 with HCM). No patient was converted to sinus rhythm by aprindine injection alone, but 8 of 9 Defibrillation by direct current (DC) shock applied for paroxysmal atrial fibrillation (Paf) has not been observed in all patients. We tried a new method for the therapy in Paf resistant to DC shock, by applying DC shock again immediately after intravenous injection of aprindine. Subjects were 9 patients with Palwho had failed to recover sinus rhythm by antiarrhythmic drug. and by the application of DC shock. Ages ranged from 48 to 83 years 7 had underling heart disease (2 patients with mitral valve disease, 2 with OMI 2 with hyperten-sion and 1 with HCM). No patient was converted to sinus rhythm by aprindine injection alone, but 8 of 9patients recovered sinus rhythm by DC shock after injection of aprindine. Blood concentration of aprin-dine ranged from 0.58 to 2.97 μg/ml. There were no significant differences in heart rate (107±39. 101±24), duration of QRS (0.10±0.03. 0.10±0.03), QT interval (0.35±0.04. 0.36±0.03) and QTc (0.44±0.07, 0.46±0.05) when coparisons were made before and after aprindine. The heart rate (107±39. 82±17) and QT interval (0.35±0.04, 0.39±0.02) were significantly changed after recovering sinus rhythm. However, there were no significant differences in duration of QRS (0.10±0.03, 0.10±0.04) and QTc (0.44±0.07. 0.44±0.04) after resto-ration to sinus rhythm. As aprindine seems to decrease the DC shock threshold, this method could be recom-mended for Palresistant to primary DC shock.