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哺乳类动物的窦房结,虽在1906年即已被发现,但对其功能一直所知不多。近年来,已了解到窦房结的确切位置、大小(约为10×4毫米)与血液供应,55％人体窦房结的血液供应来自右冠状动脉,45％来自左冠状动脉回旋支;窦房结有三种细胞(起搏细胞或P细胞,过渡细胞及心肌工作细胞);窦房结内有不止一个或一个区域的起搏细胞在工作,窦性心率的主要变化是由于一个起搏地点(P细胞)受到抑制,另一个起搏地点占统治地位所致,而不是原来的那个起搏地点的内在速率及节律改变的结果。在动物中,已进行过大量的电生理研究,但这些数据很难在人体获得或应用于人,因为即使应用心房内插管电极,也不能在距离这个起搏点的任何地方满意地记录到窦房结的作用电势,而必须穿
The sinoatrial node of mammals, although discovered in 1906, has little to do with its function. In recent years, the exact location, size (about 10 × 4 mm) of the sino-atrial node and the blood supply have been known. 55% of the human sinoatrial blood supply comes from the right coronary artery and 45% from the left circumflex coronary artery. The sinus There are three kinds of cells in the atrial node (paced cells or P cells, transitional cells and cardiac working cells); there is more than one or a region of pacemaker cells in the sinoatrial node at work, and the main change in sinus heart rate is due to a pacing site (P-cells) are suppressed, and another pacing site dominates rather than the intrinsic rate and rhythm changes of the original pacing site. In animals, a large number of electrophysiological studies have been performed, but these data are difficult to obtain or apply in humans because even with the use of an atrial intubation electrodes, they can not be satisfactorily recorded anywhere from this pacemaker point The role of sinus node potential, which must be worn