Ma Shuangtao, Rail James, Zhang Youhua
Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, New York.
Heart Rhythm O2. 2025 Feb 15;6(5):696-708. doi: 10.1016/j.hroo.2025.02.004. eCollection 2025 May.
With the discovery and validation of a novel index of dual-pathway electrophysiology, known as the His electrogram alternans, major advances have been made in understanding the electrical propagation through the atrioventricular (AV) node. At slow rates, AV conduction starts at the interatrial septal boundary of the node (superior nodal domain) and spreads toward the tricuspid annulus side (inferior nodal domain) in a direction perpendicular to the AV axis and across fiber orientation. Such activation results in an early, superior input into the superior His bundle. This is the fast pathway (FP) conduction. At fast rates, the FP wavefront gradually withdraws from the inferior nodal domain, permitting excitation formed at the crista terminalis end of the node to propagate longitudinally through the inferior nodal domain (also along the fiber orientation) to activate the inferior His bundle. This is the slow pathway (SP) conduction. The failure of FP conduction in the superior nodal domain permits retrograde invasion of the SP wavefront, forming a re-entry, but normally not AV nodal re-entrant tachycardia. The described dual-pathway electrophysiology is a normal inherent property of AV node conduction. The potential electrophysiological basis for a jump in the AV conduction curve and AV nodal re-entrant tachycardia is also discussed.
随着一种称为希氏束电图交替现象的新型双径路电生理学指标的发现和验证，在理解电信号通过房室（AV）结的传导方面取得了重大进展。在缓慢心率下，房室传导始于结的房间隔边界（上结区），并沿与房室轴垂直且与纤维方向交叉的方向朝三尖瓣环侧（下结区）传播。这种激活导致早期、上方的信号传入希氏束上部。这就是快径路（FP）传导。在快速心率下，FP波前逐渐从下结区撤回，使在结的终嵴端形成的兴奋沿纵向通过下结区（也沿纤维方向）传播，以激活希氏束下部。这就是慢径路（SP）传导。上结区的FP传导失败允许SP波前逆行侵入，形成折返，但通常不会导致房室结折返性心动过速。所描述的双径路电生理学是房室结传导的一种正常固有特性。还讨论了房室传导曲线跳跃和房室结折返性心动过速的潜在电生理基础。
