SPIRAL WAVES OF EXCITATION UNDERLIE REENTRANT ACTIVITY IN ISOLATED CARDIAC-MUSCLE
SPIRAL WAVES OF EXCITATION UNDERLIE REENTRANT ACTIVITY IN ISOLATED CARDIAC-MUSCLE
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DOI：
10.1161/01.res.72.3.631
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发表时间：
1993-03-01
影响因子：
20.1
通讯作者：
JALIFE, J
中科院分区：
文献类型：
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作者：
PERTSOV, AM;DAVIDENKO, JM;JALIFE, J
在计算机模拟和狗和羊心室心外膜肌的薄切片（几乎等于20x20x0.5 mm）中研究了折返性室性心动过速的机制。由FitzHugh-Nagumo方程建模的96 x96电耦合细胞组成的二维矩阵用于分析过早刺激诱导的椭圆螺旋波形式的自持折返活动的动力学。在均匀各向异性介质中，螺旋是固定的，并且可以无限地持续。然而，小的参数梯度的存在可能导致漂移和最终终止的螺旋在介质的边界。另一方面，螺旋可以围绕基质内的小不连续性锚和旋转。类似的结果，实验中获得的10个制剂的电活动监测电位染料和高分辨率的光学映射技术的装置;过早的刺激触发可重复的事件持续或非持续折返性心动过速的螺旋波的形式。通常，螺旋是细长的，长半轴平行于细胞的纵轴。旋转周期（183+/-68 msec [平均值+/-SD]）长于不应期（131+/-38 msec），似乎由螺旋核心的大小决定，使用新设计的“框架堆叠”图测量。螺旋波的漂移也被实验观察到。漂移速度为波传播速度的9.8%。在某些情况下，核心通过锚定到小动脉或其他异质性而变得静止，并且螺旋在很长一段时间内有节奏地旋转。然而，当漂移发生时，由于多普勒效应，激发周期的时空变化显现出来，核心前面的激发周期比核心后面的激发周期短20+/-6%。由于这些共存频率，在存在漂移螺旋波的情况下，活动的伪心电图显示出具有波动轴的“QRS波群”，这与尖端扭转型室性心动过速患者中观察到的结果相似。总体结果表明，螺旋波活动是心肌的一种特性，并表明这种活动可能是一些单形性和多形性心动过速的共同机制。
The mechanism of reentrant ventricular tachycardia was studied in computer simulations and in thin (almost-equal-to 20x20x0.5-mm) slices of dog and sheep ventricular epicardial muscle. A two-dimensional matrix consisting of 96x96 electrically coupled cells modeled by the FitzHugh-Nagumo equations was used to analyze the dynamics of self-sustaining reentrant activity in the form of elliptical spiral waves induced by premature stimulation. In homogeneous anisotropic media, spirals are stationary and may last indefinitely. However, the presence of small parameter gradients may lead to drifting and eventual termination of the spiral at the boundary of the medium. On the other hand, spirals may anchor and rotate around small discontinuities within the matrix. Similar results were obtained experimentally in 10 preparations whose electrical activity was monitored by means of a potentiometric dye and high-resolution optical mapping techniques; premature stimulation triggered reproducible episodes of sustained or nonsustained reentrant tachycardia in the form of spiral waves. As a rule, the spirals were elongated, with the major hemiaxis parallel to the longitudinal axis of the cells. The period of rotation (183+/-68 msec [mean+/-SD]) was longer than the refractory period (131+/-38 msec) and appeared to be determined by the size of the spiral's core, which was measured using a newly devised ''frame-stack'' plot. Drifting of spiral waves was also observed experimentally. Drift velocity was 9.8% of the velocity of wave propagation. In some cases, the core became stationary by anchoring to small arteries or other heterogeneities, and the spiral rotated rhythmically for prolonged periods of time. Yet, when drift occurred, spatiotemporal variations in the excitation period were manifested as a result of a Doppler effect, with the excitation period ahead of the core being 20+/-6% shorter than the excitation period behind the core. As a result of these coexisting frequencies, a pseudoelectrocardiogram of the activity in the presence of a drifting spiral wave exhibited ''QRS complexes'' with an undulating axis, which resembled those observed in patients with torsade de pointes. The overall results show that spiral wave activity is a property of cardiac muscle and suggest that such activity may be the common mechanism of a number of monomorphic and polymorphic tachycardias.