Abdollahpur Mostafa, Celotto Chiara, Sánchez Carlos, Plappert Felix, Östenson Sten, Platonov Pyotr G, Laguna Pablo, Pueyo Esther, Sandberg Frida
Department of Biomedical Engineering, Lund University, Lund, Sweden.
BSICoS Group, Aragon Institute of Engineering Research (I3A) and IIS Aragón, University of Zaragoza, Zaragoza, Spain.
Front Physiol. 2025 Jun 13;16:1498426. doi: 10.3389/fphys.2025.1498426. eCollection 2025.
This study explores transient and stationary effects of sympathetic and parasympathetic stimulation on f-wave characteristics in atrial fibrillation (AF) patients undergoing a tilt test. Transient phase is defined as the initial 2-minute interval following each postural change, reflecting immediate autonomic adaptation, whereas steady phase refers to the subsequent interval (from 3 minutes post-change until phase end) representing a stable autonomic state.
Our primary aim is to investigate how the two branches of the autonomic nervous system (ANS) influence the f-wave frequency time series ( ). An analysis of in terms of the mean over time ( ) and the magnitude of respiration-modulated variations ( ) is conducted during baseline supine rest (B), head-down tilt (HDT) and head-up tilt (HUT). We analyzed data from a previous study in which 24 patients with persistent AF underwent a tilt test protocol, during which electrocardiograms (ECGs) were recorded. A model-based method was used to extract series from the ECG. Subsequently, an orthogonal subspace projection method was employed to quantify , considering an ECG-derived respiratory signal. Electrophysiological computational simulations were conducted on 2D and 3D human atrial persistent AF models to aid the interpretation of clinical findings. Various levels of cholinergic stimulation by acetylcholine and -adrenergic stimulation by isoproterenol were tested in the models. The temporal modulation of acetylcholine, representing changes associated with respiration, was cyclically modeled using sinusoidal waveforms.
Analysis of the clinical data showed a decrease in from B to HDT and an increase from HDT to HUT. During HDT, initially increased in the transient phase before decreasing in the steady phase, then rose again during HUT. Analysis of the simulated data showed that increasing the concentration of Isoproterenol and/or acetylcholine resulted in a rise in . Additionally, the magnitude of was shown to be associated with the extent of acetylcholine fluctuation.
These results suggest that changes in f-wave frequency characteristics during HUT and HDT could be linked to changes in sympathetic activity, with parasympathetic activity possibly modulating the effects of sympathetic activity rather than being an independent driver of fibrillatory rate changes.
本研究探讨交感神经和副交感神经刺激对接受倾斜试验的心房颤动（AF）患者f波特征的瞬时和稳态影响。瞬时阶段定义为每次体位改变后的初始2分钟间隔，反映即时自主神经适应，而稳定阶段指随后的间隔（从改变后3分钟直至阶段结束），代表稳定的自主神经状态。
我们的主要目的是研究自主神经系统（ANS）的两个分支如何影响f波频率时间序列（ ）。在基线仰卧休息（B）、头低位倾斜（HDT）和头高位倾斜（HUT）期间，对 进行随时间平均（ ）和呼吸调制 变化幅度（ ）的分析。我们分析了先前一项研究的数据，该研究中24例持续性AF患者接受了倾斜试验方案，在此期间记录了心电图（ECG）。采用基于模型的方法从ECG中提取 序列。随后，采用正交子空间投影方法，考虑ECG衍生的呼吸信号来量化 。在二维和三维人体心房持续性AF模型上进行电生理计算模拟，以辅助解释临床结果。在模型中测试了不同水平的乙酰胆碱胆碱能刺激和异丙肾上腺素 -肾上腺素能刺激。使用正弦波形对代表与呼吸相关变化的乙酰胆碱的时间调制进行循环建模。
临床数据分析显示，从B到HDT， 降低，从HDT到HUT， 升高。在HDT期间， 在瞬时阶段最初升高，然后在稳定阶段降低，然后在HUT期间再次升高。模拟数据分析表明，增加异丙肾上腺素和/或乙酰胆碱的浓度会导致 升高。此外， 的幅度显示与乙酰胆碱波动程度相关。
这些结果表明，HUT和HDT期间f波频率特征的变化可能与交感神经活动的变化有关，副交感神经活动可能调节交感神经活动的影响，而不是房颤率变化的独立驱动因素。
