Department of Cardiology, Faculty of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania.
Auton Neurosci. 2012 Apr 3;167(1-2):61-5. doi: 10.1016/j.autneu.2012.01.001. Epub 2012 Jan 26.
In treatment of atrial fibrillations (AF), radiofrequency ablation (RFA) at the pulmonary vein (PV) roots isolates AF triggers in the myocardial sleeves, but also can destroy PV ganglia and branches of the intrinsic cardiac nerve plexus.
To determine the long-term impact of RFA at the PV roots on the structure of epicardial nerves located distally from the RFA site.
Five black-faced sheep underwent epicardial RFA of the left and middle PV roots. Two to 3 months after RFA, we obtained samples of epicardial nerves from remote locations of the left dorsal (LD) neural subplexus that extends along the roots of the superior PVs toward the coronary sinus (CS) and dorsal left ventricle (LV). Right atrial epicardial nerves from the right ventral (RV) neural subplexus of the ablated animals and epicardial nerves from LD neural subplexus of five additional intact sheep were used as control. Nerve morphology was examined using histochemical, immunohistochemical and transmission electron microscopy.
Histochemical acetylcholinesterase staining did not reveal any epicardial nerve alterations. However, tyrosine hydroxylase (TH) and choline acetyltransferase (ChAT) staining showed clearly the reduced numbers of TH and ChAT immunoreactive (IR) nerve fibers within epicardial nerves derived from the remote LD subplexus; control samples from all examined animals were full of evenly distributed TH-IR and ChAT-IR nerve fibers. In sharp contrast to control nerves, numerous swollen or disintegrated axons and Schwann cells with pyknotic nuclei inside unmyelinated and myelinated nerve fibers were identified by electron microscopy of ultrathin sections of epicardial nerves from the CS and LV regions in all ablated animals.
Degeneration of remote atrial and ventricular epicardial nerves is evident 2-3 months after epicardial RFA at the PV roots. Such nerves are likely to be non-functional. Therefore, long-term autonomic dysfunction is a potential risk of PV isolation by RFA.
在心房颤动（AF）的治疗中，肺静脉（PV）根部的射频消融（RFA）可隔离心肌袖套中的 AF 触发点，但也可能破坏 PV 神经节和固有心脏神经丛的分支。
确定 PV 根部 RFA 对位于 RFA 部位远端的心外膜神经结构的长期影响。
五只黑脸羊进行了左中 PV 根部的心外膜 RFA。在 RFA 后 2 至 3 个月，我们从左背（LD）神经亚丛的远离部位获得了位于左上腔静脉（CS）和左背侧心室（LV）根部附近的心外膜神经的样本。消融动物的右前（RV）神经亚丛的右心房心外膜神经和五只完整绵羊的 LD 神经亚丛的心外膜神经被用作对照。使用组织化学、免疫组织化学和透射电子显微镜检查神经形态。
乙酰胆碱酯酶组织化学染色未显示任何心外膜神经改变。然而，酪氨酸羟化酶（TH）和胆碱乙酰转移酶（ChAT）染色清楚地显示了源自远程 LD 亚丛的心外膜神经中 TH 和 ChAT 免疫反应性（IR）神经纤维数量减少；所有检查动物的对照样本均充满均匀分布的 TH-IR 和 ChAT-IR 神经纤维。与对照神经形成鲜明对比的是，在所有消融动物的 CS 和 LV 区域的心外膜神经超薄切片的电子显微镜下，识别出许多肿胀或解体的轴突和 Schwann 细胞，其髓鞘和非髓鞘神经纤维内有固缩核。
在 PV 根部的心外膜 RFA 后 2-3 个月，远程心房和心室心外膜神经的变性是明显的。这些神经可能没有功能。因此，RFA 隔离 PV 可能是自主神经功能障碍的潜在风险。
