阈下条件刺激对心房不应期的影响及对心房起搏节律的抑制作用

Effect of subthreshold conditional stimulation on atrial refractory period and atrial pacing rhythm

给１４例病人作心内电生理检查时，观察阈下条件单个刺激（Ｓｓ）和串刺激（Ｓｔ）对心房不应期和心房起搏节律的作用。初步结果表明：在Ｓ１－Ｓ２间期中加发Ｓｔ，可使心房相对不应期和有效不应期延长；且随Ｓｔ强度的增加，不应期延长量增加。在Ｓ１－Ｓ２间期中加发Ｓｓ，只有３／９例，心房相对不应期延长。另外，Ｓｔ和Ｓｓ可抑制心房起搏节律。

Effect of singlesubthreshold conditional stimulation (Ss) and train stimulation (St) on atrial refractory period and atrial pacing rhythm was observed when intracardiac electrophysiological,measurements was taken in 14 cases.The primary results indicated:That when St was introduced into S_1-S_2 interval (refractory period)it prolonged atrial relative refractory period and effective refractory period.Increase of St voltage strength was followed by increased prolongation value of atrial refractory period.When Ss was introduced into S_1-S_2 interval,it caused prolongation of atrial relative period only in 3/9 cases.On the other hand,both St and Ss could also inhibit atrial pacing rhythm.