Frame L H, Rhee E K, Fei H, Luchetti W
Department of Medicine, University of Pennsylvania, Philadelphia.
Pacing Clin Electrophysiol. 1991 Nov;14(11 Pt 2):1728-34. doi: 10.1111/j.1540-8159.1991.tb02755.x.
The effect of flecainide, 0.3 mg/L and 1.0 mg/L, on inducible nonsustained reentry was studied, in vitro, in the canine tricuspid ring. Nonsustained reentry was engineered by cutting the ring and reconnecting it with an adjustable electronic delay. Delays were used that produced reentry lasting 1-3 beats (group A), 4-10 beats (group B), and 11-25 beats (group C). Reentry was initiated multiple times at each selected delay. A proarrhythmic effect, defined as a significant increase in the duration of reentry, was observed in all 14 trials at the low dose and in two of 15 trials at the high dose in seven experiments. In four more trials a transient proarrhythmic response was seen initially during exposure to the high dose. In five of seven experiments, reentry became sustained after at least one dose of flecainide. Proarrhythmic responses resulted when flecainide increased the tachycardia cycle length more than the effective refractory period and there was less cycle length oscillation after initiation. Antiarrhythmic responses resulted either from a marked increase in effective refractory period at the site of block or production of fixed block.
研究了0.3毫克/升和1.0毫克/升氟卡尼对犬三尖瓣环体外诱导性非持续性折返的影响。通过切割环并用可调节的电子延迟重新连接来制造非持续性折返。使用的延迟产生的折返持续1 - 3次搏动（A组）、4 - 10次搏动（B组）和11 - 25次搏动（C组）。在每个选定的延迟下多次引发折返。在七个实验中，低剂量组的所有14次试验以及高剂量组的15次试验中的两次观察到促心律失常作用，定义为折返持续时间显著增加。在另外四次试验中，在高剂量暴露初期观察到短暂的促心律失常反应。在七个实验中的五个实验中，至少一剂氟卡尼后折返变为持续性。当氟卡尼使心动过速周期长度增加超过有效不应期且起始后周期长度振荡减少时会产生促心律失常反应。抗心律失常反应要么源于阻滞部位有效不应期的显著增加，要么源于产生固定阻滞。
