心律失常产生的机制心律失常产生的主要原因,系由于心脏组织的自律性,传导性及兴奋性的改变。自律性:取决于4相坡度,坡度愈陡,自律性愈高。愈平、愈低。传导性:取决于0相快 Na~+内流速度,内流速度愈快,振幅愈大,传导速度愈快。内流速度愈慢,振幅愈低,传导速度愈慢。兴奋性:即应激性。①取决于静息电位与阈电位水平间的距离:静息电位愈低(即 Mechanism of arrhythmia The main cause of arrhythmia, due to the self-discipline of heart tissue, conductivity and excitability changes. Self-discipline: Depending on the 4-phase slope, the steeper the slope, the higher the self-discipline. The more flat, the lower. Conductivity: Depends on the 0 phase Na ~ + fast inflow velocity, the faster the inflow velocity, the greater the amplitude, the faster the conduction velocity. The slower the inflow velocity, the lower the amplitude, the slower the conduction velocity. Excitability: that is stress. ① depends on the distance between the resting potential and the threshold potential level: the lower the resting potential (ie