塩酸ピルジカイニドの心房細動閾値に及ぼす効果の検討

Effect of Pilsicainide Hydrochloride on Atrial Fibrillation Threshold

　発作性心房細動（Paf）患者12名を対象に，塩酸ピルジカイニド投与前後の心房細動閾値（AFT），心房間伝導時間（Inter-ACT），右心房有効不応期（RAERP）を比較検討した．右心耳に刺激間隔500msecの基本刺激を8回与えた後，50 Hzの持続刺激を1秒間加えた．刺激電流は2mAより1mAずつ上昇させ，30秒間以上持続する心房細動もしくは心房粗動を誘発しえた最小の電流値をAFTと定義した．AFTは塩酸ピルジカイニド投与後有意に上昇した（5.3±2.0mA→6.8±3.6mA）．また，Inter-ACTは塩酸ピルジカイニド投与後有意に延長したが（122±21msec→149±33 msec），RAERPは不変であった（218±24msec→217±27 msec）．なお，AFTとInter-ACT,AFTとRAERPの間では有意な相関はみられなかった．塩酸ピルジカイニドは心房間伝導時間を延長させるとともに心房細動閾値を上昇させ，心房受攻性を低下させることが示唆された．

To inventigate the electrophysiologic effects of pil-sicainide hydrochloride on atrial fibrillation, we compared atrial fibrillation threshold (AFT), right atrial effective refractory period (RAERP), and inter-atrial conduction time (Inter-ACT) before and after the administration of pilsicainide in 12 patients with lone paroxysmal atrial fibrillation. The following electrophysiologic study was performed before and after the administration of the drug as the paced cycle length of 500msec. First, RAERP was measured.