Characteristics of the temporal and spatial excitable gap in anisotropic reentrant circuits causing sustained ventricular tachycardia.
Characteristics of the temporal and spatial excitable gap in anisotropic reentrant circuits causing sustained ventricular tachycardia.
复制标题
引起持续性室性心动过速的各向异性折返回路中时间和空间可兴奋间隙的特征。
DOI：
10.1161/01.res.82.2.279
复制
发表时间：
1998
影响因子：
20.1
通讯作者：
Wit,AL
中科院分区：
文献类型：
--
作者：
Peters,NS;Coromilas,J;Hanna,MS;Josephson,ME;Costeas,C;Wit,AL
-重入电路的可激发间隙具有时间(电路可激发的周期长度期间的时间)和空间(在给定时间可激发的电路的长度)属性。我们确定了由非均匀各向异性引起的重入电路中可激发带隙的时间和空间特性。结扎犬冠状动脉左前降支造成心肌梗死模型。4天后，在程序性刺激诱发的持续性室性心动过速期间，用多电极阵列在梗塞的心外膜交界区标测折返回路。在心动过速时，通过刺激折返回路周围的部位和折返回路中的部位来激发早搏，并绘制出它们在回路中的传导特征。所有电路在至少部分电路中都有一个暂时可兴奋的间隙，这允许过早的脉冲进入电路。通过测量早搏脉冲的传导速度来识别时间间隙的完全和部分可兴奋节段；在完全可兴奋的区域，传导等于自然折返波前，而在部分可兴奋的区域，传导慢于折返波前。在一些电路中，整个电路都存在时间间隙，允许整个电路在一系列过早耦合间隔内被重置，尽管间隙的大小在不同的位置有所不同。在其他电路中，局部位置的间隙变得如此之小，以至于即使过早的脉冲可能进入电路，电路也无法重置。过早的脉冲可能会终止电路中的再入，这些电路可以重置或不可重置。我们还发现了一个显著的空间间隙，这是通过确定循环波阵面的头部和尾部之间的距离来识别的，循环波阵面的头部可以在激活图上定位，而尾部是早搏波前进入回路的位置距离头部最远的位置。空间间隙在电路的不同部分也可能有所不同。因此，非均匀各向异性重入电路具有时间和空间可激发的间隙，其全部和部分可激发分量在电路的不同部分改变。
—The excitable gap of a reentrant circuit has both temporal (time during the cycle length that the circuit is excitable) and spatial (length of the circuit that is excitable at a given time) properties. We determined the temporal and spatial properties of the excitable gap in reentrant circuits caused by nonuniform anisotropy. Myocardial infarction was produced in canine hearts by ligation of the left anterior descending coronary artery. Four days later, reentrant circuits were mapped in the epicardial border zone of the infarcts with a multielectrode array during sustained ventricular tachycardia induced by programmed stimulation. During tachycardia, premature impulses were initiated by stimulation at sites around and in the reentrant circuits, and their conduction characteristics in the circuit were mapped. All circuits had a temporal excitable gap in at least part of the circuit, which allowed premature impulses to enter the circuit. Completely and partially excitable segments of the temporal gap were identified by measuring conduction velocity of the premature impulses; conduction was equal to the native reentrant wave front in completely excitable regions and slower than the reentrant wave front in partially excitable regions. In some circuits, a temporal gap existed throughout the circuit, permitting the entire circuit to be reset over a range of premature coupling intervals, although the size of the gap varied at different sites. In other circuits, the gap became so small at local sites that even though premature impulses could enter the circuit, the circuit could not be reset. Premature impulses could terminate reentry in circuits that could be reset or not. We also found a significant spatial gap, which was identified by determining the distance between the head of the circulating wave front, which could be located on the activation map, and its tail, which was the site most distal from the head as located by the site of entry of the premature wave front into the circuit. The spatial gap could also vary in different parts of the circuit. Therefore, nonuniform anisotropic reentrant circuits have both a temporal and spatial excitable gap with fully and partially excitable components that change in different parts of the circuit.