论文部分内容阅读
已知具备传导异常是导致折返性心律失常的主要原因。按过去的观念,传导紊乱必由离子通道变化所引起,如快反应细胞由于种种原因转变为慢反应细胞等等。但即使动作电位完全正常的心房心室肌细胞,在一次过早激动后也可诱发折返性心律失常。折返可发生在2mm~2范围内。折返环路也并非固定不变。还发现在某些条件下,心肌的传导速度可比慢反应细胞组成的房室结更慢。说明有些经典的观念需要修正。 Spach是当前研究心脏兴奋传导领域的权威。10年前他即发现兴奋扩布方向与心肌纤维排列的阴向不同,测得的同一心肌细胞动作电位的V_max即不同。以后证实心肌在微小范围内(<200mμ)不能按“合胞体”概念理解为均一的传导媒体(mcdium),而具各向异性特性。该特性与折返性心律失常的发生或终止均有极为密切的关系。本文是Spach为Circulation杂志写的“编辑部评论”,总结了近10年来这方面的实验室工作,对临床工作者在理解和治疗折返性心律失常时有重要借鉴价值。在阅读此文之前,可先参阅68页的名词解释,以便理解文中的术语。
It is known that having a conduction abnormality is the main cause of reentrant arrhythmias. According to the concept of the past, conduction disorders will be caused by changes in ion channels, such as rapid response of cells due to various reasons into slow response cells and so on. However, even atrial ventricular myocytes with completely normal action potentials may induce reentrant arrhythmias after a premature exacerbation. Reentry can occur in the range of 2mm ~ 2. Reentry loop is not fixed. It has also been found that under certain conditions, the conduction velocity of the myocardium can be slower than that of the atrioventricular node composed of the slow responding cells. Some classic ideas need to be amended. Spach is the current authority in the field of cardiac excitation. Ten years ago, he found that the direction of excitement and the direction of myocardial fibers aligned with the different Yin, measured the same cardiomyocyte action potential V_max is different. It was later demonstrated that myocardium can not be understood as a homogeneous mcdium with the concept of “syncytia” in a very small area (<200mμ) but with anisotropic properties. This property is associated with the occurrence or termination of reentrant arrhythmias. This is Spach’s editorial comment for Circulation, which summarizes lab work in this area in the past 10 years and is of great value to clinicians in understanding and treating reentrant arrhythmias. Before reading this article, you can refer to the explanation of the nomenclature on page 68 in order to understand the terminology in the text.