Oreto G, Luzza F, Satullo G, Arrigo F
G Ital Cardiol. 1985 Jul;15(7):732-4.
A patient with a malfunctioning pacemaker due to lead insulation defect is reported. High voltage stimuli were always effective, while when the pulse amplitude was reduced to 3.8 volt stimuli were uneffective except when occurring after extremely long asystolic pauses. An advanced exit block (up to 7:1) thus occurred. Late lowering of the myocardial threshold of excitability could be explained by slow spontaneous diastolic depolarization occurring in myocardial fibers surrounding the tip of the electrode.
报道了一名因导线绝缘缺陷导致起搏器功能障碍的患者。高电压刺激总是有效的，而当脉冲幅度降至3.8伏时，除了在极长的心脏停搏后出现刺激外，刺激均无效。因此出现了高度的传出阻滞（高达7:1）。心肌兴奋性阈值的后期降低可以用围绕电极尖端的心肌纤维中发生的缓慢自发舒张期去极化来解释。
