Mechanism of spontaneous termination of functional reentry in isolated canine right atrium. Evidence for the presence of an excitable but nonexcited core.
Mechanism of spontaneous termination of functional reentry in isolated canine right atrium. Evidence for the presence of an excitable but nonexcited core.
复制标题
离体犬右心房功能折返自发终止的机制。
DOI：
10.1161/01.cir.94.8.1962
复制
发表时间：
1996
期刊：
影响因子：
37.8
通讯作者：
Karagueuzian,HS
中科院分区：
文献类型：
--
作者：
Ikeda,T;Uchida,T;Hough,D;Lee,JJ;Fishbein,MC;Mandel,WJ;Chen,PS;Karagueuzian,HS
背景根据折返的螺旋波假说，功能折返的核心是兴奋但不兴奋的。我们试图确定核心是否仍然兴奋和是否激励的核心由外部波阵面导致终止的折返在atrium.Methods和ResultsIn九个孤立的犬右endoadrenal心房组织（3.8 3.2厘米宽），折返诱导过早点刺激（S2）。使用509个双极电极（1.6 mm分辨率）可视化等时激动图和激动模式的动态。8次规则心搏后应用S2诱发折返，平均周期长度为162±20 ms（15次）。折返有一个大的兴奋间隙（93±26 ms），这是由两倍于阈值刺激水平的早期夺获确定的。波前围绕其旋转的中心区域（核心）的平均表面积为12±3 mm2。位于折返核心的电描记图记录无或极低幅度电位。在15个事件中的13个事件中，当外部新的波前与原始波前合并并激发核心时，再入终止。核心激发引起原始波前的破坏，并且新形成的波前在77±18 ms内在组织边界处消失。当一个与折返波阵面相反方向传播的外部新波阵面与折返波阵面的前缘碰撞时，折返突然终止。一个可激发但未被激发的核和一个大的可激发能隙。折返可以通过直接激发核心将波前转移到组织边界或通过与外部新波前碰撞来终止。
BackgroundAccording to the spiral wave hypothesis of reentry, the core of functional reentry remains excitable but not excited. We sought to determine whether the core remains excitable and whether excitation of the core by an outside wave front leads to termination of the reentry in the atrium.Methods and ResultsIn nine isolated canine right endocardial atrial tissues (3.8 by 3.2 cm wide), reentry was induced by a premature point stimulus (S2). The isochronal activation maps and dynamics of the activation patterns were visualized with the use of 509 bipolar electrodes (1.6-mm resolution). The S2applied after 8 regular beats induced reentry with a mean cycle length of 162±20 ms (15 episodes). Reentry had a large excitable gap (93±26 ms) as determined by early capture with twice the level of threshold stimuli. The central area (core) around which the wave fronts rotated had a mean surface area of 12±3 mm2. The electrograms located in the core of the reentry registered no or very low amplitude potentials. In 13 of 15 episodes, reentry terminated when an outside new wave front merged with the original wave front and excited the core. Core excitation caused disruption of the original wave front, and the newly formed wave front(s) vanished at the tissue border within 77±18 ms. In 2 episodes, reentry terminated abruptly when an outside new wave front propagating in a direction opposite to the reentrant wave front collided with the leading edge of the reentrant wave front.ConclusionsFunctional reentry in the atrium is compatible with a spiral wave of excitation with an excitable but nonexcited core and a large excitable gap. Reentry may be terminated either by direct excitation of the core that displaces the wave front to the tissue border or by collision with an outside new wave front.