慢性心力衰竭发生率和死亡率均较高，夜间睡眠中反复发生的呼吸暂停和缺氧是促进心力衰竭恶化的因素之一。中枢性睡眠呼吸暂停（central sleep apnea ,CSA）为起源于脑干呼吸控制中枢障碍的呼吸暂停，表现为呼吸减弱或停止。在普通人群中CSA患病率很低，但在慢性心力衰竭患者中则很高，且常常以陈-施呼吸（Cheyne-Stokes respiration，CSR），即CSR-CSA形式出现。CSA可进一步加重心力衰竭，因此越来越受到重视[1]。
睡眠过程中反复出现呼吸暂停造成的间歇低氧是阻塞性睡眠呼吸暂停低通气综合征( OSAHS) 的主要病理生理学特点, 它能够导致自主神经, 特别是交感神经兴奋性异常增高[1] , 后者可能是OSAHS合并心血管疾病包括高血压、充血性心力衰竭、心肌梗死以及心律失常的主要危险因素之一[2,3] 。现将慢性间歇低氧( chronic intermittent hypoxia,CIH) 所致交感神经异常兴奋的相关研究作一综述。
阻塞性睡眠呼吸暂停低通气综合征( OSAHS) 是心血管疾病的独立危险因素[1,2 ]。睡眠过程中反复发生氧饱和度降低和频繁觉醒是心血管损伤的病理生理基础。OSAHS 血管损害的早期改变可表现为血管僵硬度增加, 对亚临床血管病变患者开展早期动脉弹性功能检测及早进行干预, 可有效预防心血管疾病的发生。本文就常用的无创动脉硬化检测lt;br /gt;技术及其对OSAHS 心血管损伤的评估相关研究进展进行综述。
【Abstract】Objective To explore the differential diagnostic value of major fibrinolytic parameters in pleural fluid. Methods Tissue-type plasminogen activator( t-PA) and plasminogen activator inhibitor-1( PAI-1) in pleural fluid at the first thoracentesis were measured with ELISA and D-dimer was measured with immunoturbidimetry. Results Eighty-four patients with pleural effusion were enrolled, among which 40 with malignant effusion, 33 with infectious effusion and 11 with transudative effusion. t-PA level was higher in malignant and transudative pleural fluid than that in infectious pleural fluid[ ( 52. 49 ±31. 46) ng /mL and ( 58. 12 ±23. 14) ng /mL vs ( 37. 39 ±22. 44) ng /mL, P lt; 0. 05] , but was not statistically different between malignant pleural fluid and transudative ( P gt; 0. 05) . PAI-1 level was higher in malignant and infectious pleural fluid than that in transudative [ ( 164. 86 ±150. 22) ng/mL and ( 232. 42 ±175. 77) ng/mL vs ( 46. 38 ±16. 13) ng/mL, P lt; 0. 01] , but was not statistically different between malignant and infectious pleural fluid( P gt;0. 05) . D-dimer levels in the three types of pleural fluid were significantly different, which was ( 23. 66 ±25. 18) mg/L, ( 6. 36 ±10. 87) mg/L and ( 66. 90 ±42. 17) mg/L in malignant, transudative and infectious pleural fluid, respectively. As single-item detection for malignant pleural fluid, the cutoff of t-PA was gt; 38. 7 ng/mL( area under ROC curve was 64. 0 ) , with sensitivity of 60. 0% , specificity of 63. 6%, positive predictive value of 66. 7%, negative predictive value of 56. 8% and accuracy of 61. 6% .The cutoff of D-dimer was lt; 27. 0 mg/L( area under ROC curve was 85. 5) , with sensitivity of 84. 8% ,specificity of 72. 5% , positive predictive value of 85. 3% , negative predictive value of 71. 8% and accuracy of78.1%. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of combined examination( t-PA + D-dimer) were 92. 5% , 60. 6% , 74. 0% , 87. 0% , 78. 1% , respectively.Conclusions The t-PA, PAI-1 and D-dimer levels are significantly different in the three types of pleural fluid. The detection of fibrinolytic parameters in pleural fluid, especially the value of D-dimer,may be helpful in the differential diagnosis of pleural effusion.