目的:研究不同类型的房颤(AF)对人外周血CD34+造血祖细胞(CD34+HPCs)的影响,以及持续心房快速起搏犬心肌基质细胞衍生因子-1(SDF-1)及其受体CXCR4的表达,初步探讨CD34+HPCs及SDF-1/CXCR4在AF时心肌损伤修复中的作用。方法:应用流式细胞术测定阵发性AF患者组(n=35)、持续性AF患者组(n=35)及窦性心律者对照组(n=30)外周血中CD34+HPCs的百分含量;并对持续性AF患者组中24例患者成功进行体外直流电复律后48 h,测定外周血中CD34+HPCs的百分含量。另外,将成年健康杂种犬13条随机分为两组:即快速起搏组(n=7)和假手术组(n=6),均开胸后于右心耳缝植AOO型起搏器,快速起搏组以400次/min起搏6周,假手术组不起搏。应用RT-PCR测定左心耳和左心房CXCR4 mRNA的表达水平,用蛋白质免疫印迹法检测左心房SDF-1蛋白的表达。结果:持续性AF患者组外周血中CD34+HPCs的百分含量明显高于阵发性AF患者组和对照组(P<0.05);而后两组间无差别。持续性AF患者成功进行体外直流电复律后48 h,外周血中CD34+HPCs的百分含量较复律前明显下降(P<0.05)。快速起搏组犬左心耳和左心房CXCR4 mRNA表达的水平明显高于假手术组(P<0.05),左心耳增高16.7%,左心房增高18.8%;SDF-1蛋白质表达的水平亦明显高于假手术组(P<0.01)。结论:持续性AF患者外周血中CD34+HPCs的数量增加;心房快速起搏犬心房SDF-1/CXCR4的表达增加。CD34+HPCs和SDF-1/CXCR4可能参与了持续性AF患者心房损伤时心肌组织的修复过程。 Objective: To investigate the effects of different types of atrial fibrillation (AF) on CD34 + hematopoietic progenitor cells (CD34 + HPCs) in human peripheral blood and the effect of sustained atrial pacing myocardial canine stromal cell derived factor-1 (SDF-1) CXCR4 expression, to explore the role of CD34 + HPCs and SDF-1 / CXCR4 in the repair of myocardial injury during AF. Methods: Flow cytometry was used to determine the percentage of CD34 + HPCs in the peripheral blood of patients with paroxysmal AF (n = 35), patients with persistent AF (n = 35) and sinus rhythm control (n = 30) The percentage of CD34 + HPCs in peripheral blood was measured 48 hours after DC in vitro. In addition, 13 adult healthy hybrid dogs were randomly divided into two groups: fast paced group (n = 7) and sham operation group (n = 6) Fast paced group pacing 400 times / min for 6 weeks, sham group without pacing. The expression of CXCR4 mRNA in left atrial appendage and left atrium was detected by RT-PCR. The expression of SDF-1 protein in left atrium was detected by Western blotting. Results: The percentages of CD34 + HPCs in peripheral blood of patients with persistent AF were significantly higher than those of patients with paroxysmal AF (P <0.05). There was no difference between the two groups. The percentage of CD34 + HPCs in peripheral blood decreased significantly (P <0.05) compared with those before cardioversion at 48 h after continuous cardioversion in patients with persistent AF. The expression of CXCR4 mRNA in left atrial appendage and left atrium in fast pacing group was significantly higher than that in sham operation group (P <0.05), the left atrial appendage was increased by 16.7% and the left atrium was increased by 18.8%. SDF-1 protein expression was also significantly higher Sham operation group (P <0.01). CONCLUSION: The number of CD34 + HPCs in peripheral blood of patients with persistent AF increases. The atrial SDF-1 / CXCR4 expression in atrial canine is rapidly increased. CD34 + HPCs and SDF-1 / CXCR4 may be involved in the repair process of myocardial tissue in patients with persistent AF.