van Hunnik Arne, Zeemering Stef, Podziemski Piotr, Simons Jorik, Gatta Giulia, Hannink Laura, Maesen Bart, Kuiper Marion, Verheule Sander, Schotten Ulrich
Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, Netherlands.
Front Physiol. 2018 Jul 27;9:947. doi: 10.3389/fphys.2018.00947. eCollection 2018.
Electro-anatomical mapping of the atria is used to identify the substrate of atrial fibrillation (AF). Targeting this substrate by ablation in addition to pulmonary vein ablation did not consistently improve outcome in clinical trials. Generally, the assessment of the substrate is based on short recordings (≤10 s, often even shorter). Thus, targeting the AF substrate assumes spatiotemporal stationarity but little is known about the variability of electrophysiological properties of AF over time. Atrial fibrillation (AF) was maintained for 3-4 weeks after pericardial electrode implantation in 12 goats. Within a single AF episode 10 consecutive minutes were mapped on the left atrial free wall using a 249-electrode array (2.25 mm inter-electrode spacing). AF cycle length, fractionation index (FI), lateral dissociation, conduction velocity, breakthroughs, and preferentiality of conduction (Pref) were assessed per electrode and AF property maps were constructed. The Pearson correlation coefficient (PCC) between the 10 AF-property maps was calculated to quantify the degree spatiotemporal stationarity of AF properties. Furthermore, the number of waves and presence of re-entrant circuits were analyzed in the first 60-s file. Comparing conduction patterns over time identified recurrent patterns of AF with the use of recurrence plots. The averages of AF property maps were highly stable throughout the ten 60-s-recordings. Spatiotemporal stationarity was high for all 6 property maps, PCC ranged from 0.66 ± 0.11 for Pref to 0.98 ± 0.01 for FI. High stationarity was lost when AF was interrupted for about 1 h. However, the time delay between the recorded files within one episode did not affect PCC. Yet, multiple waves (7.7 ± 2.3) were present simultaneously within the recording area and during 9.2 ± 11% of the analyzed period a re-entrant circuit was observed. Recurrent patterns occurred rarely and were observed in only 3 out of 12 goats. During non-self-terminating AF in the goat, AF properties were stationary. Since this could not be attributed to stable recurrent conduction patterns during AF, it is suggested that AF properties are determined by anatomical and structural properties of the atria even when the conduction patterns are very variable.
心房的电解剖标测用于识别房颤（AF）的基质。在临床试验中，除肺静脉消融外，通过消融靶向该基质并不能持续改善预后。一般来说，对基质的评估基于短记录（≤10秒，通常甚至更短）。因此，靶向房颤基质假定其具有时空稳定性，但对于房颤电生理特性随时间的变异性知之甚少。在12只山羊的心包电极植入后，房颤持续维持3 - 4周。在单个房颤发作期间，使用249电极阵列（电极间距2.25毫米）对左心房游离壁进行连续10分钟的标测。评估每个电极的房颤周期长度、碎裂指数（FI）、横向解离、传导速度、突破点和传导优先性（Pref），并构建房颤特性图。计算10个房颤特性图之间的皮尔逊相关系数（PCC），以量化房颤特性的时空稳定程度。此外，在最初的60秒文件中分析波的数量和折返环的存在情况。通过使用递归图比较不同时间的传导模式，识别房颤的复发模式。在整个十个60秒记录中，房颤特性图的平均值高度稳定。所有六个特性图的时空稳定性都很高，PCC范围从Pref的0.66±0.11到FI的0.98±0.01。当房颤中断约1小时时，高稳定性丧失。然而，一个发作内记录文件之间的时间延迟并不影响PCC。然而，在记录区域内同时存在多个波（7.7±2.3），并且在9.2±11%的分析时间段内观察到一个折返环。复发模式很少出现，仅在12只山羊中的3只中观察到。在山羊的非自限性房颤期间，房颤特性是稳定的。由于这不能归因于房颤期间稳定的复发传导模式，因此表明即使传导模式非常多变，房颤特性也由心房的解剖和结构特性决定。
