要了解心律失常的机理,首先应了解正常心脏活动节律产生的原理。心肌细胞分为两类,一类是构成心房和心室壁的普通肌纤维,具有收缩功能;另一类是特殊心肌纤维,能产生和传导冲动,从而控制心脏的节律活动,称为心脏的特殊传导系统。这两类细胞在静息状态下,其膜内外存在的电位差叫静息电位(或称膜电位、极化状态)。目前认为,它是由于细胞内外 k~+ 浓度的差别以及静息时细胞 To understand the mechanism of arrhythmia, we should first understand the principle of normal heart rhythm. Myocardial cells are divided into two categories, one is the common muscle fibers that make up the atrium and the ventricular wall, with contractile function; the other is a special myocardial fiber that can generate and transmit impulses to control the heart’s rhythmic activity, called the heart’s special conduction system. These two types of cells in resting state, the potential difference between the inside and outside the membrane called resting potential (or membrane potential, polarization state). It is currently believed that it is due to differences in intracellular and extracellular k ~ + concentrations as well as resting cells