Faculty of Medicine, The University of Tokyo, 7 -3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
Comput Biol Med. 2021 Mar;130:104217. doi: 10.1016/j.compbiomed.2021.104217. Epub 2021 Jan 19.
Precise analysis of cardiac spiral wave (SW) dynamics is essential for effective arrhythmia treatment. Although the phase singularity (PS) point in the spatial phase map has been used to determine the cardiac SW center for decades, quantitative detection algorithms that assume PS as a point fail to trace complex and rapid PS dynamics. Through a detailed analysis of numerical simulations, we examined our hypothesis that a boundary of spatial phase discontinuity induced by a focal conduction block exists around the moving SW center in the phase map.
In a numerical simulation model of a 2D cardiac sheet, three different types of SWs (short wavelength; long wavelength; and low excitability) were induced by regulating ion channels. Discontinuities of all boundaries among adjacent cells at each instance were evaluated by calculating the phase bipolarity (PB). The total amount of phase transition (PTA) in each cell during the study period was evaluated.
Pivoting, drifting, and shifting SWs were observed in the short-wavelength, low-excitability, and long-wavelength models, respectively. For both the drifting and shifting cases, long high-PB edges were observed on the SW trajectories. In all cases, the conduction block (CB) was observed at the same boundaries. These were also identical to the boundaries in the PTA maps.
The analysis of the simulations revealed that the conduction block at the center of a moving SW induces discontinuous boundaries in spatial phase maps that represent a more appropriate model of the SW center than the PS point.
精确分析心脏螺旋波（SW）动力学对于有效的心律失常治疗至关重要。尽管空间相位图中的相位奇点（PS）点已被用于确定心脏 SW 中心数十年，但假设 PS 为点的定量检测算法无法追踪复杂和快速的 PS 动力学。通过对数值模拟的详细分析，我们检验了我们的假设，即在相位图中，移动 SW 中心周围存在由局灶性传导阻滞引起的空间相位不连续边界。
在 2D 心脏薄片的数值模拟模型中，通过调节离子通道诱导三种不同类型的 SW（短波长；长波长；低兴奋性）。通过计算相位双极性（PB）评估每个实例中相邻细胞之间所有边界的不连续性。评估每个细胞在研究期间的总相位转换量（PTA）。
在短波长、低兴奋性和长波长模型中观察到了旋转、漂移和移动 SW。对于漂移和移动情况，在 SW 轨迹上观察到长的高 PB 边缘。在所有情况下，都观察到传导阻滞（CB）在相同的边界上。这些边界也与 PTA 图谱中的边界相同。
对模拟的分析表明，移动 SW 中心的传导阻滞在空间相位图谱中诱导不连续边界，这比 PS 点更能代表 SW 中心的更合适模型。
