Department of Biomedical Engineering, 36 S. Wasatch Drive, SMBB 3100, University of Utah, Salt Lake City, UT 84112, USA.
Nora Eccles Harrison Cardiovascular Research and Training Institute, 95 S 2000 E, Bldg. 500, University of Utah, Salt Lake City, UT 84112, USA.
Europace. 2024 Nov 1;26(11). doi: 10.1093/europace/euae269.
Rotational re-entries and ectopic foci, or 'drivers', are proposed mechanisms for persistent atrial fibrillation (persAF), but driver-based interventions have had mixed success in clinical trials. Selective targeting of drivers with multi-month stability may improve these interventions, but no prior work has investigated whether drivers can be stable on such a long timescale.
We hypothesized that drivers could recur even several months after initial observation.
We performed serial electrophysiology studies on paced canines (n = 18, 27-35 kg) at 1-, 3-, and 6 months post-initiation of continual persAF. Using a high-density 64-electrode catheter, we captured endocardial electrograms in the left atrium (LA) and right atrium (RA) to determine the presence of drivers at each major anatomical site. We defined drivers that were repeatedly observed across consecutive studies to be recurrent. The mean probability that any driver would recur was 66% (LA: 73%, RA: 41%). We also found evidence of 'multi-recurring' drivers, i.e. those seen in all three studies. Multi-recurring drivers constituted 53% of initially observed drivers with at least one found in 92% of animals, and we found more multi-recurring drivers per animal than predicted by random chance (2.6 ± 1.5 vs. 1.2 ± 1.1, P < 0.001). Driver sites showed more enhancement than non-drivers during late gadolinium enhancement-magnetic resonance imaging (P = 0.04), but we observed no relationship between enhancement and driver recurrence type.
We observed recurring drivers over a 6-month period at fixed locations, confirming our hypothesis. We also found drivers to be associated with fibrosis, implying a structural basis.
旋转再进入和异位灶（即“驱动灶”）被认为是持续性心房颤动（persAF）的机制，但基于驱动灶的干预措施在临床试验中的效果不一。对具有数月稳定性的驱动灶进行选择性靶向治疗可能会改善这些干预措施，但之前没有研究调查驱动灶是否可以在如此长的时间尺度上保持稳定。
我们假设在初始观察后数月，驱动灶可能会再次出现。
我们对起搏犬（n=18，27-35kg）进行了一系列电生理研究，这些犬在持续性房性颤动起始后 1、3 和 6 个月进行研究。使用高密度 64 电极导管，我们在左心房（LA）和右心房（RA）捕获心内膜电图，以确定每个主要解剖部位是否存在驱动灶。我们将在连续研究中反复观察到的驱动灶定义为复发性驱动灶。任何驱动灶再次出现的平均概率为 66%（LA：73%，RA：41%）。我们还发现了“多复发性”驱动灶的证据，即在所有三次研究中都观察到的驱动灶。多复发性驱动灶占最初观察到的驱动灶的 53%，在 92%的动物中至少发现了一个，并且我们发现每个动物的多复发性驱动灶多于随机预测的（2.6±1.5 比 1.2±1.1，P<0.001）。与非驱动灶相比，驱动灶部位在晚期钆增强磁共振成像（P=0.04）中显示出更多的增强，但我们没有观察到增强与驱动灶复发类型之间的关系。
我们在固定部位观察到 6 个月内反复出现的驱动灶，证实了我们的假设。我们还发现驱动灶与纤维化有关，这意味着存在结构基础。
