Ventricular Echoes: Evidence For Dissociation Of Conduction and Reentry Within the Av Node
Ventricular Echoes: Evidence For Dissociation Of Conduction and Reentry Within the Av Node
复制标题
心室回声：房室结内传导分离和折返的证据
作者：
R. Mignone;A. Wallace
这些实验旨在进一步研究房室在心脏中传播的双重途径的概念，并确定心房是否是用于心室回声的再入途径的必要环节。研究在麻醉和清醒的狗身上进行，记录电极植入心房，他束和右心室。当配对刺激（V1V2）以适当的延迟施加到心室时，第二次刺激的心跳之后是一个非刺激的心室回声。回声反应起源于室上。在回声配对刺激过程中，在V2逆行反应到来之前对心房的刺激会在预期的回声到来之前产生一个传播性的心室搏动。回声后立即刺激心房与明显的房室传导异常有关。这些观察结果支持房室结在功能上至少可分离为两条通路的结论。在不消除回声的情况下，可以使中庭变得坚硬。这一发现表明心房本身不参与心室回声的再入路径。
These experiments were designed to examine further the concept of a dual pathway for AV transmission in the heart, and to determine whether or not the atrium is a necessary link in the reentry pathway used for a ventricular echo. Studies were performed on anesthetized and awake dogs with recording electrodes implanted on the atrium, bundle of His, and right ventricle. When paired stimuli (V1V2) were applied to the ventricle with an appropriate delay, the second stimulated beat was followed by a nonstimulated ventricular echo. The echo response was of supraventricular origin. During paired stimulation with echoes, stimulation of the atrium prior to arrival of the retrograde response to V2 produced a propagated ventricular beat in advance of the expected echo. Stimulation of the atrium immediately after an echo was associated with apparent supernormal AV conduction. These observations support the conclusion that the AV node can be dissociated functionally into at least two pathways. It was possible to render the atrium refractory without abolishing the echo. This finding indicates that the atrium per se does not participate in the reentry path used for ventricular echo.