IMB, University of Bordeaux, 351 Cours de la Liberation, Talence 33405, France Carmen, Inria Bordeaux Sud-Ouest, 200 Avenue de la Vieille Tour, Talence 33405, France Electrophysiology and Heart Modeling Institute LIRYC, PTIB-Campus Xavier Arnozan, Avenue du Haut Lévêque, Pessac 33600, France
Carmen, Inria Bordeaux Sud-Ouest, 200 Avenue de la Vieille Tour, Talence 33405, France Electrophysiology and Heart Modeling Institute LIRYC, PTIB-Campus Xavier Arnozan, Avenue du Haut Lévêque, Pessac 33600, France Hôpital Haut-Lévèque CHU Bordeaux, University Bordeaux Segalen, Avenue de Magellan, Pessac 33604, France.
Europace. 2014 Nov;16 Suppl 4:iv21-iv29. doi: 10.1093/europace/euu256.
Atrial numerical modelling has generally represented the organ as either a surface or tissue with thickness. While surface models have significant computational advantages over tissue models, they cannot fully capture propagation patterns seen in vivo, such as dissociation of activity between endo- and epicardium. We introduce an intermediate representation, a bilayer model of the human atria, which is capable of recreating recorded activation patterns.
We simultaneously solved two surface monodomain problems by formalizing an optimization method to set a coupling term between them. Two different asymptotically equivalent numerical implementations of the model are presented. We then built a geometrically and electrophysiologically detailed model of the human atria based on CT data, including two layers of fibre directions, major muscle bundles, and discrete atrial coupling. We adjusted parameters to recreate clinically measured activation times. Activation was compared with a monolayer model. Activation was fit to the physiological range measured over the entire atria. The crista terminalis and pectinate muscles were important for local right atrial activation, but did not significantly affect total activation time. Propagation in the bilayer model was similar to that of a monolayer, but with noticeable difference, due to three-dimensional propagation where fibre direction changed abruptly across the wall, resulting in a slight dissociation of activity.
Atrial structure plays the dominant role in determining activation. A bilayer model is able to take into account transmural heterogeneities, while maintaining the low computational load associated with surface models.
心房数值模型通常将器官表示为具有厚度的表面或组织。虽然表面模型比组织模型具有显著的计算优势，但它们无法完全捕捉到体内可见的传播模式，例如心内膜和心外膜之间的活动分离。我们引入了一种中间表示，即人类心房的双层模型，它能够重现记录的激活模式。
我们通过形式化一种优化方法来设置它们之间的耦合项，同时解决两个表面单域问题。提出了两种不同的渐近等效数值实现模型。然后，我们根据 CT 数据构建了一个具有详细几何形状和电生理特性的人类心房模型，包括两层纤维方向、主要肌肉束和离散的心房耦合。我们调整参数以重现临床测量的激活时间。将激活与单层模型进行比较。将激活拟合到整个心房测量的生理范围内。心耳终嵴和梳状肌对右心房局部激活很重要，但对总激活时间没有显著影响。双层模型中的传播与单层模型相似，但由于纤维方向在壁上突然变化的三维传播，导致活动略有分离，因此存在明显差异。
心房结构在确定激活方面起着主导作用。双层模型能够考虑到贯穿壁的非均质性，同时保持与表面模型相关的低计算负荷。
