Applied Signal Processing Group, Swiss Federal Institute of Technology, CH-1015 Lausanne, Switzerland.
Europace. 2014 May;16(5):766-73. doi: 10.1093/europace/euu003.
Preliminary studies showed that the septum area was the only location allowing local capture of both the atria during rapid pacing of atrial fibrillation (AF) from a single site. The present model-based study investigated the influence of atrial substrate on the ability to capture AF when pacing the septum.
Three biophysical models of AF with an identical anatomy from human atria but with different AF substrates were used: (i) AF based on multiple wavelets, (ii) AF based on heterogeneities in vagal activation, (iii) AF based on heterogeneities in repolarization. A fourth anatomical model without Bachmann's bundle (BB) was also implemented. Rapid pacing was applied from the septum at pacing cycle lengths in the range of 50-100% of AF cycle length. Local capture was automatically assessed with 24 pairs of electrodes evenly distributed on the atrial surface. The results were averaged over 16 AF simulations. In the homogeneous substrate, AF capture could reach 80% of the atrial surface. Heterogeneities degraded the ability to capture during AF. In the vagal substrate, the capture tended to be more regular and the degradation of the capture was not directly related to the spatial extent of the heterogeneities. In the third substrate, heterogeneities induced wave anchorings and wavebreaks even in areas close to the pacing site, with a more dramatic effect on AF capture. Finally, BB did not significantly affect the ability to capture.
Atrial fibrillation substrate had a significant effect on rapid pacing outcomes. The response to therapeutic pacing may therefore be specific to each patient.
初步研究表明，在从单个部位对心房颤动（AF）进行快速起搏时，只有在隔区才能局部捕获到两个心房。本基于模型的研究调查了在起搏间隔时，心房基质对捕获 AF 的能力的影响。
使用了三个具有相同人类心房解剖结构但具有不同 AF 基质的双物理模型：（i）基于多个波的 AF，（ii）基于迷走神经激活异质性的 AF，（iii）基于复极异质性的 AF。还实现了第四个没有 Bachmann 束（BB）的解剖模型。快速起搏应用于从间隔以起搏周期长度在 AF 周期长度的 50-100%范围内进行。使用均匀分布在心房表面的 24 对电极自动评估局部捕获。结果在 16 个 AF 模拟中平均。在均匀基质中，AF 捕获可达到心房表面的 80%。异质性降低了在 AF 期间捕获的能力。在迷走神经基质中，捕获倾向于更规则，并且捕获的退化与异质性的空间范围没有直接关系。在第三个基质中，即使在靠近起搏部位的区域，异质性也会引起波锚定和波破裂，对 AF 捕获的影响更为显著。最后，BB 对捕获能力没有显著影响。
心房颤动基质对快速起搏结果有重大影响。因此，治疗性起搏的反应可能因患者而异。
