心房颤动对微创二尖瓣术后患者静态肺功能及运动耐量的影响

目的:探究房颤对微创二尖瓣术后患者的静态肺功能及运动耐量水平的影响。方法:微创二尖瓣术后患者30例,按有无房颤分为两组,各15例,两组间基本情况保持均衡。所有患者在2013年1月1日至2014年9月30日期间进行静态肺功能及症状限制的极量心肺运动测试。肺功能由用力肺活量、第一秒用力呼气量、两者实测值分别占预计值的百分比,及1秒率表示;运动耐量用峰值时公斤摄氧量(peak VO2/kg),表示,通气效率用无氧阈时二氧化碳通气当量(VE/VCO2@AT)表示。结果:房颤组表现为轻度限制性肺通气障碍,而窦律组平均肺通气功能正常;房颤组运动耐量水平显著低于窦律组,两组peak VO2/kg分别为17.34±2.82 ml·kg-1·min-1、20.35±4.13 ml·kg-1·min-(1P=0.03);两组间VE/VCO2@AT也有显著性差异(34.48±4.16 vs 29.80±4.51,P0.01)。结论:二尖瓣术后合并房颤的患者,其肺容积及运动耐量明显低于窦律的患者,运动耐量下降的主要机制为心排血量减少。

Effects of atrial fibrillation on static pulmonary function and exercise endurance in minimally invasive mitral valve surgery patients

Abstract Objective: To explore the effects of atrial fibrillation (Af) on static pulmonary function and exercise endurance in post minimally invasive mitral valve surgery (MIMVS) patients. Method: Fifteen post-MIMVS patients with Af (Af group) were matched to fifteen post-MIMVS subjects with sinus rhythm (SR group) according to general information. All subjects underwent static pulmonary function test and symptom-limited cardiopulmonary exercise testing from Jan 1st, 2014 to Sept 30th, 2014. Variables, forced vital capacity, forced expiration volume in 1 second and percentages of their predicted values, FEV1/FVC ratio, peak oxygen uptake per kilogram (peak VO2/kg), ventilation to carbon dioxide ratio at anaerobic threshold (VE/VCO2 @AT) were obtained. Result: Pulmonary function in Af group was lower than that in SR group, but this difference was not significant. Exercise endurance, as measured by peak VO2/kg (17.34±2.82 ml·kg-1·min-1 vs 20.35±4.13 ml·kg-1·min-1, P= 0.03), was significantly lower in Af group. Additionally, there was a significant difference of ventilation efficiency, indicated by VE/VCO2@AT (34.48 ± 4.16 vs 29.80 ± 4.51, P<0.01), between these two groups. Conclusion: MIMVS patients with Af have significantly impaired lung volume and exercise endurance. The mechanism of reduced exercise endurance among Af patients is the declined cardiac output.