Abstract：
The pulmonary impairment in patients with bronchoconstriction induced by eucapnic voluntary hyperpnea(EVH) goes beyond the respiratory system, also impairing autonomic nervous modulation. This study aimed to evaluate the behavior of cardiac autonomic modulation in young asthmatics with and without EIB after the EVH test.
A cross-sectional study design using 54 asthmatics(51.9% female), aged between 10 and 19 years, investigated with the EVH test. Forced expiratory volume in one second(FEV1) was measured at 5, 10, 15, and 30 min after EVH. Heart rate variability(HRV) measures of time were assessed pre and 30 min-post EVH. The diagnosis of Exercise-Induced bronchoconstriction with underlying clinical asthma(EIBA) was confirmed by a fall in FEV1 ≥10% compared to baseline.
Thirty(55.5%) asthmatics had EIBA. Subjects with EIBA have reduced mean of the R-R intervals in relation to baseline until 15 minutes after EVH. Individuals without EIBA had increased parasympathetic activity compared to baseline(rMSSD) from 5 min after EVH(p < 0.05). This parasympathetic activity increase in relation to baseline was seen in individuals with EIBA after 25 minutes (rMSSD = 49.9 ± 5.3 vs 63.5 ± 7.2, p < 0.05).
Young asthmatics with EIBA present a delay in the increase of the parasympathetic component after EVH when compared to asthmatics without EIBA.
A cross-sectional study design using 54 asthmatics(51.9% female), aged between 10 and 19 years, investigated with the EVH test. Forced expiratory volume in one second(FEV1) was measured at 5, 10, 15, and 30 min after EVH. Heart rate variability(HRV) measures of time were assessed pre and 30 min-post EVH. The diagnosis of Exercise-Induced bronchoconstriction with underlying clinical asthma(EIBA) was confirmed by a fall in FEV1 ≥10% compared to baseline.
Thirty(55.5%) asthmatics had EIBA. Subjects with EIBA have reduced mean of the R-R intervals in relation to baseline until 15 minutes after EVH. Individuals without EIBA had increased parasympathetic activity compared to baseline(rMSSD) from 5 min after EVH(p < 0.05). This parasympathetic activity increase in relation to baseline was seen in individuals with EIBA after 25 minutes (rMSSD = 49.9 ± 5.3 vs 63.5 ± 7.2, p < 0.05).
Young asthmatics with EIBA present a delay in the increase of the parasympathetic component after EVH when compared to asthmatics without EIBA.
摘要：
■由高血压自愿呼吸过度（EVH）引起的支气管收缩患者的肺损害超出了呼吸系统，也损害自主神经调节。这项研究旨在评估EVH测试后有或没有EIB的年轻哮喘患者的心脏自主神经调节行为。
■使用54名哮喘患者（51.9％为女性）进行的横断面研究设计，年龄在10至19岁之间，用EVH试验进行调查。在EVH后5、10、15和30分钟测量一秒内的用力呼气量（FEV1）。在EVH之前和之后30分钟评估时间的心率变异性（HRV）测量值。与基线相比，FEV1下降≥10％，证实了运动性支气管收缩伴潜在临床哮喘（EIBA）的诊断。
■30例（55.5%）哮喘患者患有EIBA。具有EIBA的受试者具有相对于基线的R-R间隔的平均值降低,直到EVH后15分钟。没有EIBA的个体从EVH后5分钟开始，与基线（rMSSD）相比，副交感神经活动增加（p<0.05）。这种副交感神经活性相对于基线的增加在25分钟后在患有EIBA的个体中观察到(rMSSD=49.9±5.3vs63.5±7.2,p<0.05)。
■与没有EIBA的哮喘患者相比，患有EIBA的年轻哮喘患者在EVH后副交感神经成分的增加延迟。
■使用54名哮喘患者（51.9％为女性）进行的横断面研究设计，年龄在10至19岁之间，用EVH试验进行调查。在EVH后5、10、15和30分钟测量一秒内的用力呼气量（FEV1）。在EVH之前和之后30分钟评估时间的心率变异性（HRV）测量值。与基线相比，FEV1下降≥10％，证实了运动性支气管收缩伴潜在临床哮喘（EIBA）的诊断。
■30例（55.5%）哮喘患者患有EIBA。具有EIBA的受试者具有相对于基线的R-R间隔的平均值降低,直到EVH后15分钟。没有EIBA的个体从EVH后5分钟开始，与基线（rMSSD）相比，副交感神经活动增加（p<0.05）。这种副交感神经活性相对于基线的增加在25分钟后在患有EIBA的个体中观察到(rMSSD=49.9±5.3vs63.5±7.2,p<0.05)。
■与没有EIBA的哮喘患者相比，患有EIBA的年轻哮喘患者在EVH后副交感神经成分的增加延迟。
