Atrial Fibrosis and Conduction Slowing in the Left Atrial Appendage of Patients Undergoing Thoracoscopic Surgical Pulmonary Vein Isolation for Atrial Fibrillation
Atrial Fibrosis and Conduction Slowing in the Left Atrial Appendage of Patients Undergoing Thoracoscopic Surgical Pulmonary Vein Isolation for Atrial Fibrillation
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DOI：
10.1161/circep.114.001752
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发表时间：
2015-04-01
影响因子：
8.4
通讯作者：
de Groot, Joris R.
中科院分区：
文献类型：
--
作者：
Krul, Sebastien P. J.;Berger, Wouter R.;de Groot, Joris R.
背景-心房纤维化是心房颤动（AF）患者促炎性基质的重要组成部分。我们研究了间质纤维化对AF患者左心耳传导速度（CV）的影响。方法和结果：在AF手术中获得了35个左心耳。以每分钟100次心跳的速度灌注和刺激制剂。用光学标测记录激活。测量纵向CV（CVL）、横向CV（CVT）和激活时间（>2 mm距离）。间质胶原定量和定性分级。用免疫化学方法评估成纤维细胞和肌成纤维细胞的存在。平均CVL为0.55+/-0.22 m/s，平均CVT为0.25+/-0.15 m/s，平均激动时间为9.31+/-5.45 ms。纤维化程度与CV或患者特征无关。与薄的间质胶原束相比，厚的左心耳CVL更高（0.77+/-0.22对0.48+/-0.19 m/s; P=0.012），在持续性房颤患者中更常见。（P=0.47），但间质胶原束较厚与较薄的患者的激活时间分别为14.93+/-4.12和7.95+/-4.12 ms（P=0.004）。成纤维细胞大量存在，并与厚的间质胶原链的存在（P=0.008）。肌成纤维细胞没有检测到在左心耳。结论，在房颤患者，厚的间质胶原链与较高的CVL和激活时间增加。我们的观察结果表明，局部间质纤维化的严重程度和结构与心房传导异常相关，为心房折返提供了致炎基质。
Background-Atrial fibrosis is an important component of the arrhythmogenic substrate in patients with atrial fibrillation (AF). We studied the effect of interstitial fibrosis on conduction velocity (CV) in the left atrial appendage of patients with AF.Methods and Results-Thirty-five left atrial appendages were obtained during AF surgery. Preparations were superfused and stimulated at 100 beats per minute. Activation was recorded with optical mapping. Longitudinal CV (CVL), transverse CV (CVT), and activation times (>2 mm distance) were measured. Interstitial collagen was quantified and graded qualitatively. The presence of fibroblasts and myofibroblasts was assessed immunohistochemically. Mean CVL was 0.55+/-0.22 m/s, mean CVT was 0.25+/-0.15 m/s, and the mean activation time was 9.31+/-5.45 ms. The amount of fibrosis was unrelated to CV or patient characteristics. CVL was higher in left atrial appendages with thick compared with thin interstitial collagen strands (0.77+/-0.22 versus 0.48+/-0.19 m/s; P=0.012), which were more frequently present in persistent patients with AF. CVT was not significantly different (P=0.47), but activation time was 14.93+/-4.12 versus 7.95+/-4.12 ms in patients with thick versus thin interstitial collagen strands, respectively (P=0.004). Fibroblasts were abundantly present and were associated with the presence of thick interstitial collagen strands (P=0.008). Myofibroblasts were not detected in the left atrial appendage.Conclusions-In patients with AF, thick interstitial collagen strands are associated with higher CVL and increased activation time. Our observations demonstrate that the severity and structure of local interstitial fibrosis is associated with atrial conduction abnormalities, presenting an arrhythmogenic substrate for atrial re-entry.