Nakai Toshiko, Chandy Joby, Nakai Kazuhiko, Bellows Wayne H, Flachsbart Keith, Lee Randall J, Leung Jacqueline M
Division of Cardiovascular Medicine, Nihon University School of Medicine, Tokyo, Japan.
Cardiology. 2007;108(2):90-6. doi: 10.1159/000095936. Epub 2006 Sep 28.
Atrial fibrillation (AF) is a common complication after coronary artery bypass graft (CABG) surgery. Despite the prevalence of AF occurring after cardiac surgery, its pathophysiology is incompletely understood. Our previous study demonstrated that age and left atrial enlargement were independent predictors of postoperative AF. Accordingly, the purpose of this study was to determine whether cellular changes such as fibrosis and/or hypertrophy occurred in the atrium in patients who subsequently developed postoperative AF. Right atrial appendage tissue was obtained during atriotomy in patients undergoing elective CABG surgery. Quantitative assessment of atrial fibrosis was performed with Sirius red stain, and atrial cell diameter was measured with the HE stain. Linear regression, t test, chi2 test or Fisher exact test were used for statistical analysis. Sixty-one patients (mean age 71 +/- 8 years) were studied. Increasing age was significantly associated with fibrosis (beta 0.3, 95% CI: 0.06-0.55, p = 0.017). The amount of right atrial fibrosis tended to correlate with the incidence of postoperative AF (p = 0.08). Cell diameter was not significantly different between patients with versus without postoperative AF (p = 0.85). These results suggest that the age-related atrial fibrosis rather than cellular hypertrophy may be important in the pathogenesis of AF after CABG surgery and should be further investigated.
心房颤动（AF）是冠状动脉旁路移植术（CABG）后常见的并发症。尽管心脏手术后房颤很常见，但其病理生理学尚未完全阐明。我们之前的研究表明，年龄和左心房扩大是术后房颤的独立预测因素。因此，本研究的目的是确定在随后发生术后房颤的患者心房中是否发生了如纤维化和/或肥大等细胞变化。在接受择期CABG手术的患者进行心房切开术时获取右心耳组织。用天狼星红染色对心房纤维化进行定量评估，并用苏木精-伊红染色测量心房细胞直径。采用线性回归、t检验、卡方检验或Fisher精确检验进行统计分析。共研究了61例患者（平均年龄71±8岁）。年龄增加与纤维化显著相关（β0.3，95%CI：0.06-0.55，p = 0.017）。右心房纤维化程度与术后房颤发生率呈正相关趋势（p = 0.08）。术后发生房颤和未发生房颤的患者之间细胞直径无显著差异（p = 0.85）。这些结果表明，与年龄相关的心房纤维化而非细胞肥大可能在CABG术后房颤的发病机制中起重要作用，值得进一步研究。
