Schoels W, Becker R
Department of Cardiology, University of Heidelberg, Germany.
J Cardiovasc Electrophysiol. 1998 Aug;9(8 Suppl):S13-7.
Atrial flutter is due to large single reentrant loops, typically oriented around the caval veins and a line of functional conduction block in between. These reentrant circuits can easily be terminated by properly timed extra beats colliding in the antidromic direction with the reentrant orthodromic wavefront and being blocked in the orthodromic direction within the area of slow conduction. Due to the complex situation in atrial fibrillation with multiple, ever-changing wavelets and a marked functional inhomogeneity of the atrial tissue, these simple concepts do not apply. However, regional control of atrial tissue by rapid pacing is feasible during atrial fibrillation, and through a multisite approach, this pacing modality might lead to a situation where the remaining nonentrained atrial tissue is just no longer reaching the critical mass. Single-site, dual-site, and biatrial pacing seems to reduce the incidence of atrial fibrillation recurrences. Specific advantages and disadvantages of each approach still need to be elucidated. Apart from preventing bradycardia, preventive pacing modes reduce intra-atrial conduction times and might reduce intra-atrial dispersion of refractoriness. Still, the specific mechanisms relevant for their effectiveness need further clarification.
心房扑动是由大的单个折返环引起的，通常围绕腔静脉以及其间的一条功能性传导阻滞线。这些折返环路可通过适时的额外搏动在逆向方向与折返的正向波阵面碰撞并在缓慢传导区域内被正向阻滞而轻易终止。由于心房颤动时情况复杂，存在多个不断变化的小波且心房组织有明显的功能不均一性，这些简单概念并不适用。然而，在心房颤动期间通过快速起搏对心房组织进行区域控制是可行的，并且通过多部位方法，这种起搏方式可能会导致剩余未被激动的心房组织不再达到临界质量的情况。单部位、双部位和双心房起搏似乎可降低心房颤动复发的发生率。每种方法的具体优缺点仍需阐明。除了预防心动过缓外，预防性起搏模式可缩短心房内传导时间，并可能减少心房内不应期离散。不过，其有效性的具体机制仍需进一步阐明。
