Instituto Interuniversitario de Investigación en Bioingeniería y Tecnología Orientada al Ser Humano (I3BH), Universitat Politècnica de València, Valencia, Spain.
PLoS One. 2013;8(2):e50883. doi: 10.1371/journal.pone.0050883. Epub 2013 Feb 11.
The most common sustained cardiac arrhythmias in humans are atrial tachyarrhythmias, mainly atrial fibrillation. Areas of complex fractionated atrial electrograms and high dominant frequency have been proposed as critical regions for maintaining atrial fibrillation; however, there is a paucity of data on the relationship between the characteristics of electrograms and the propagation pattern underlying them. In this study, a realistic 3D computer model of the human atria has been developed to investigate this relationship. The model includes a realistic geometry with fiber orientation, anisotropic conductivity and electrophysiological heterogeneity. We simulated different tachyarrhythmic episodes applying both transient and continuous ectopic activity. Electrograms and their dominant frequency and organization index values were calculated over the entire atrial surface. Our simulations show electrograms with simple potentials, with little or no cycle length variations, narrow frequency peaks and high organization index values during stable and regular activity as the observed in atrial flutter, atrial tachycardia (except in areas of conduction block) and in areas closer to ectopic activity during focal atrial fibrillation. By contrast, cycle length variations and polymorphic electrograms with single, double and fragmented potentials were observed in areas of irregular and unstable activity during atrial fibrillation episodes. Our results also show: (1) electrograms with potentials without negative deflection related to spiral or curved wavefronts that pass over the recording point and move away, (2) potentials with a much greater proportion of positive deflection than negative in areas of wave collisions, (3) double potentials related with wave fragmentations or blocking lines and (4) fragmented electrograms associated with pivot points. Our model is the first human atrial model with realistic fiber orientation used to investigate the relationship between different atrial arrhythmic propagation patterns and the electrograms observed at more than 43000 points on the atrial surface.
人类最常见的持续性心律失常是房性心动过速，主要是心房颤动。已提出复杂碎裂心房电图和高频优势频率区域是维持心房颤动的关键区域；然而，关于电描记图的特征与其潜在传播模式之间的关系的数据很少。在这项研究中，开发了一个真实的人类心房 3D 计算机模型来研究这种关系。该模型包括具有纤维方向、各向异性电导率和电生理异质性的真实几何形状。我们通过应用瞬态和连续异位活动模拟了不同的心动过速发作。在整个心房表面上计算了电描记图及其主导频率和组织指数值。我们的模拟显示，在稳定和规则活动期间，电描记图具有简单的电位，几乎没有或没有周期长度变化，窄的频率峰值和高的组织指数值，如在心房扑动、房性心动过速（除传导阻滞区域外）和局灶性心房颤动期间靠近异位活动的区域中观察到的。相比之下，在心房颤动发作期间不规则和不稳定活动的区域中观察到具有周期长度变化和单极、双极和碎裂电位的多形性电描记图。我们的结果还表明：（1）与在记录点上方经过并远离的螺旋或弯曲波前相关的无负偏转电位的电描记图，（2）在波碰撞区域中具有比负向更大比例的正向偏转的电位，（3）与波碎裂或阻挡线相关的双极电位，以及（4）与枢轴点相关的碎裂电描记图。我们的模型是第一个使用真实纤维方向的人类心房模型，用于研究不同心房心律失常传播模式与在心房表面上 43000 多个点观察到的电描记图之间的关系。
