体位性心动过速综合征儿童及青少年在直立试验中血流动力学变化

Hemodynamic changes in standing-up test of children and adolescents with postural tachycardia syndrome

目的:分析体位性心动过速综合征(postural tachycardia syndrome, POTS)儿童及青少年直立试验过程中血流动力学变化及不同心脏指数(cardiac index, CI)患者血流动力学指标的差异。方法:回顾性分析26例POTS患者与12例健康对照者间直立试验过程中总外周血管阻力指数(total peripheral vascular resistance index, TPVRI)、心率和血压的变化,并比较两组间各指标变化趋势。根据每位POTS患者直立试验过程中CI变化趋势将患者分为CI降低组(14例)与CI未降低组(12例),分析两组患者在直立试验过程中CI、TPVRI、心率、血压变化,并比较两组间各指标变化趋势。结果: POTS患者在直立试验过程中CI显著下降( F =6.936, P =0.001),心率明显增快( F = 113.926 , P <0.001),收缩压明显降低( F =6.049, P <0.001),而TPVRI ( F =2.031, P =0.138)和舒张压( F =2.018, P =0.113)无明显变化。健康对照组CI在直立后显著升高( F =3.646, P =0.016),同时心率明显增快( F = 43.970, P <0.001),收缩压( F =4.043, P =0.020)和舒张压( F =8.627, P <0.001)均明显升高,TPVRI ( F = 1.688, P =0.190)无明显变化。POTS患者与健康对照组比较,CI ( F =6.221, P= 0.001)、心率( F =6.203, P < 0.001)和收缩压( F =7.946, P <0.001)随时间变化趋势显著不同,而TPVRI和舒张压在两组间的变化趋势差异无统计学意义( P >0.05)。CI降低组与CI未降低组POTS患者在直立试验中CI变化趋势差异有统计学意义( F = 14.723, P <0.001),前者直立后收缩压明显降低( F =8.010, P <0.001),而后者却无明显变化( F =0.612, P = 0.639 ), TPVRI、心率和舒张压在CI降低组与CI未降低组间随时间变化趋势差异无统计学意义( P >0.05)。年龄是POTS患者直立后CI呈下降趋势的独立影响因素( P =0.013, OR =2.233;95% CI :1.183~4.216)。结论: POTS患者在直立试验过程中存在明显的血流动力学变化,不同患者心输出量变化可能不同,年龄是心输出量下降的独立影响因素。

Objective: To explore the hemodynamic changes in standing-up test of children and adolescents with postural tachycardia syndrome (POTS) and to compare hemodynamic parameters of POTS patients with decreased cardiac index (CI) and those with not-decreased CI. Methods: A retrospective study was conducted to show the trends of CI, total peripheral vascular resistance index (TPVRI), heart rate and blood pressure in standing-up test of 26 POTS patients and 12 healthy controls, and to compare them between the two groups. The POTS patients were divided into two groups based on CI decreasing or not in standing-up test, namely decreased CI group (14 cases) and not-decreased CI group (12 cases). The trends of the above mentioned hemodynamic parameters in standing-up test were observed and compared between decreased CI group and not-decreased CI group. Results: In standing-up test for all the POTS patients, CI ( F =6.936, P =0.001) and systolic blood pressure ( F =6.049, P <0.001) both decreased significantly, and heart rate increased obviously ( F =113.926 , P <0.001). However, TPVRI ( F =2.031, P =0.138) and diastolic blood pressure ( F =2.018, P =0.113) had no significant changes. For healthy controls, CI ( F =3.646, P =0.016), heart rate ( F =43.970, P <0.001), systolic blood pressure ( F =4.043, P =0.020) and diastolic blood pressure ( F =8.627, P <0.001) all increased significantly in standing-up test. TPVRI ( F =1.688, P =0.190) did not change obviously. The changing trends of CI ( F =6.221, P= 0.001), heart rate ( F =6.203, P <0.001) and systolic blood pressure ( F =7.946, P <0.001) over time were significantly different between the patients and healthy controls, however, no difference was found in TPVRI and diastolic blood pressure ( P > 0.05). Among the POTS patients, CI was significantly different between decreased CI group and not-decreased CI group ( F =14.723, P <0.001). Systolic blood pressure of the former decreased obviously ( F = 8.010 , P <0.001), but it did not change obviously in the latter ( F =0.612, P =0.639). Furthermore, none of the changes of TPVRI, heart rate and diastolic blood pressure in standing-up test were significantly different between the two groups ( P > 0.05). Age was an independent factor for decreased CI patients ( P =0.013, OR =2.233;95% CI , 1.183 to 4.216). Conclusion: POTS patients experience vital hemodynamic changes in standing-up test, part of them suffering from decreased CI, but others from not-decreased CI. Age is an independent factor for patients suffering from decreased CI.