Zhao Jichao, Krueger Martin W, Seemann Gunnar, Meng Shu, Zhang Henggui, Dössel Olaf, LeGrice Ian J, Smaill Bruce H
Auckland Bioengineering Institute, University of Auckland, New Zealand.
Annu Int Conf IEEE Eng Med Biol Soc. 2012;2012:6365-8. doi: 10.1109/EMBC.2012.6347450.
Anatomically realistic computational models provide a powerful platform for investigating mechanisms that underlie atrial rhythm disturbances. In recent years, novel techniques have been developed to construct structurally-detailed, image-based models of 3D atrial anatomy. However, computational models still do not contain full descriptions of the atrial intramural myofiber architecture throughout the entire atria. To address this, a semi-automatic rule-based method was developed for generating multi-layer myofiber orientations in the human atria. The rules for fiber generation are based on the careful anatomic studies of Ho, Anderson and co-workers using dissection, macrophotography and visual tracing of fiber tracts. Separately, a series of high color contrast images were obtained from sheep atria with a novel confocal surface microscopy method. Myofiber orientations in the normal sheep atria were estimated by eigen-analyis of the 3D image structure tensor. These data have been incorporated into an anatomical model that provides the quantitative representation of myofiber architecture in the atrial chambers. In this study, we attempted to compare the two myofiber generation approaches. We observed similar myo-bundle structure in the human and sheep atria, for example in Bachmann's bundle, atrial septum, pectinate muscles, superior vena cava and septo-pulmonary bundle. Our computational simulations also confirmed that the preferential propagation pathways of the activation sequence in both atrial models is qualitatively similar, largely due to the domination of the major muscle bundles.
解剖学上逼真的计算模型为研究心房节律紊乱的潜在机制提供了一个强大的平台。近年来，已开发出新技术来构建基于图像的三维心房解剖结构详细模型。然而，计算模型仍未完整描述整个心房壁内肌纤维结构。为解决这一问题，开发了一种基于规则的半自动方法来生成人类心房中的多层肌纤维方向。纤维生成规则基于Ho、Anderson及其同事使用解剖、宏观摄影和纤维束视觉追踪进行的细致解剖学研究。另外，采用一种新型共聚焦表面显微镜方法从绵羊心房获取了一系列高颜色对比度图像。通过对三维图像结构张量进行特征分析来估计正常绵羊心房中的肌纤维方向。这些数据已被纳入一个解剖模型，该模型提供了心房腔中肌纤维结构的定量表示。在本研究中，我们试图比较这两种肌纤维生成方法。我们在人类和绵羊心房中观察到了相似的肌束结构，例如在巴赫曼束、房间隔、梳状肌、上腔静脉和隔肺束中。我们的计算模拟还证实，两种心房模型中激活序列的优先传播途径在定性上相似，这主要是由于主要肌束的主导作用。
