Arribas F, Cosio F G, Palacios J, Alonso M, Lopez-Gil M
Eur Heart J. 1986 Feb;7(2):158-64. doi: 10.1093/oxfordjournals.eurheartj.a062039.
Slow conduction of early extrastimuli and short refractory periods are some of the factors underlying atrial fibrillation in man. In order to study the effect of ajmaline, a class I antiarrhythmic agent, on these variables, we have performed electrophysiologic studies in 13 patients with and without atrial arrhythmias, before and after the intravenous administration of 1 mg kg-1 of ajmaline chlorhydrate. During paced rhythm with a 600 ms cycle length, extrastimuli were applied to the right atrial appendage, and conduction to the low septal right atrium and the coronary sinus were measured. Ajmaline prolonged P wave duration from 111 +/- 15 to 140 +/- 24 ms (P less than 0.001), conduction of baseline stimuli to low septal right atrium from 69 +/- 14 to 95 +/- 21 ms (P less than 0.001) and to coronary sinus from 127 +/- 18 to 165 +/- 29 ms (P less than 0.001). Atrial effective refractory period increased from 207 +/- 23 to 255 +/- 27 ms (P less than 0.001). Maximum conduction delay of early extrastimuli decreased at the low septal right atrium from 43 +/- 22 to 29 +/- 16 ms (P less than 0.25) and at the coronary sinus from 47 +/- 22 to 21 +/- 14 ms (P less than 0.001). These results show interesting electrophysiologic effects of ajmaline on atrial tissue, with reversion of some of the abnormalities underlying atrial fibrillation, and suggest an antiarrhythmic effect.
早期额外刺激的缓慢传导和较短的不应期是人类房颤的部分潜在因素。为了研究Ⅰ类抗心律失常药物阿义马林对这些变量的影响，我们对13例有或无房性心律失常的患者在静脉注射1mg/kg盐酸阿义马林前后进行了电生理研究。在600ms周期长度的起搏心律期间，将额外刺激施加于右心耳，并测量其向低位间隔右心房和冠状窦的传导。阿义马林使P波时限从111±15ms延长至140±24ms（P<0.001），基线刺激向低位间隔右心房的传导时间从69±14ms延长至95±21ms（P<0.001），向冠状窦的传导时间从127±18ms延长至165±29ms（P<0.001）。心房有效不应期从207±23ms增加至255±27ms（P<0.001）。早期额外刺激在低位间隔右心房的最大传导延迟从43±22ms降至29±16ms（P<0.25），在冠状窦从47±22ms降至21±14ms（P<0.001）。这些结果显示了阿义马林对心房组织有趣的电生理作用，逆转了房颤的一些潜在异常，并提示其具有抗心律失常作用。
