Penn State Heart and Vascular Institute, Penn State College of Medicine , Hershey, Pennsylvania.
Am J Physiol Heart Circ Physiol. 2019 Mar 1;316(3):H476-H484. doi: 10.1152/ajpheart.00470.2018. Epub 2018 Dec 7.
Radiofrequency catheter ablation (RFCA) is a frequently performed procedure in patients with atrial fibrillation. Prior studies have shown that the RFCA may directly stimulate vagal afferents during the procedure, whereas the vagal tone assessed by heart rate variability (HRV) is lowered weeks after the RFCA procedure. The effects of RFCA performed in the left atrium on sympathetic nerve activity have not been assessed. In the present study, we hypothesized that RFCA would lower muscle sympathetic nerve activity (MSNA) during ablation and would raise MSNA 1 day postablation. A total of 18 patients were studied. In protocol 1 ( n = 10), electrocardiogram, blood pressure, and MSNA in the peroneal nerve were recorded through the RFCA procedure performed in the electrophysiology laboratory. In protocol 2, eight patients were studied before the procedure and 1 day postablation. RFCA led to a decrease in MSNA immediately after the procedure (25.4 ± 3.2 to 17.2 ± 3.8 bursts/min, P < 0.05). Cardiac parasympathetic activity was determined using indexes of HRV and increased during the procedure. One day postablation, MSNA was above baseline values (21.3 ± 3.7 to 35.7 ± 2.6 bursts/min, P < 0.05). HRV indexes of cardiac parasympathetic activity fell, and the HRV index of sympathovagal balance was not significantly altered. The results show that RFCA raised cardiac parasympathetic activity and decreased MSNA during the procedure. One day postablation, MSNA rose and cardiac parasympathetic activity fell. In addition, RFCA evokes differentiated sympathetic responses directed to the heart and skeletal muscles. NEW & NOTEWORTHY The effects of radiofrequency catheter ablation performed in the left atrium on muscle sympathetic nerve activity (MSNA) have not been assessed. The results of this study show that radiofrequency catheter ablation raised cardiac parasympathetic activity and decreased MSNA during the procedure. One day postablation, MSNA rose and cardiac parasympathetic activity fell. We speculate that the partial autonomic afferent denervation induces these effects on autonomic activity.
射频导管消融（RFCA）是房颤患者经常进行的一种手术。先前的研究表明，RFCA 过程中可能会直接刺激迷走传入神经，而射频消融手术后数周，心率变异性（HRV）评估的迷走神经张力会降低。RFCA 对左心房交感神经活动的影响尚未得到评估。在本研究中，我们假设 RFCA 会降低消融过程中的肌肉交感神经活动（MSNA），并会在消融后 1 天提高 MSNA。共有 18 名患者参与了研究。在方案 1（n=10）中，通过在电生理实验室进行的 RFCA 过程，记录了心电图、血压和腓肠神经中的 MSNA。在方案 2 中，8 名患者在术前和术后 1 天进行了研究。RFCA 导致手术后立即降低 MSNA（25.4±3.2 至 17.2±3.8 次/分，P<0.05）。使用 HRV 指数确定心脏副交感神经活动，并在手术过程中增加。消融后 1 天，MSNA 高于基线值（21.3±3.7 至 35.7±2.6 次/分，P<0.05）。心脏副交感神经活动的 HRV 指数下降，而交感神经-迷走神经平衡的 HRV 指数没有明显改变。结果表明，RFCA 在手术过程中提高了心脏副交感神经活动并降低了 MSNA。消融后 1 天，MSNA 升高，心脏副交感神经活动下降。此外，RFCA 引起了针对心脏和骨骼肌的不同的交感神经反应。本研究首次评估了左心房射频导管消融对肌肉交感神经活动（MSNA）的影响。结果表明，射频导管消融在手术过程中提高了心脏副交感神经活动并降低了 MSNA。消融后 1 天，MSNA 升高，心脏副交感神经活动下降。我们推测，部分自主传入神经纤维切断会对自主活动产生这些影响。
