Background: Equine asthma in severe form (severe equine asthma [sEA]) shares remarkable similarities with human asthma. Human studies detected changes in the autonomic nervous system function in asthmatic patients based on heart rate variability (HRV) analysis.
Study design: Observational study.
Objectives: To investigate the relationship between sEA and HRV in horses.
Methods: Twenty horses diagnosed with sEA and 20 asymptomatic (non-sEA) horses were investigated. SEA horses showed clinical signs. The RR intervals of the ECG were recorded for 1 h at rest between 9 AM and 11 AM using a heart rate (HR) monitor. HRV data were calculated using Kubios software. Parameters recorded for the sEA and non-sEA groups were compared using one-way MANOVA model. The significance level was set at α = 0.05.
Results: SD2 (mean 99.6 ± SD 25.3 vs. 42.5 ± 17.1), SDNN (82.7 ± 20.7 vs. 41.3 ± 14.3), TINN (398.1 ± 104.9 vs. 209.3 ± 71.9), SD2/SD1 ratio (1.7 ± 0.2 vs. 1.1 ± 0.3), Total power (4740.2 ± 1977.9 vs. 1503.0 ± 1179.3), LF (2415.3 ± 1072.4 vs. 707.4 ± 649.9), SD1 (60.9 ± 15.9 vs. 39.2 ± 14.1), RMSSD (86.0 ± 22.6 vs. 55.3 ± 19.8) and HF (1575.8 ± 902.5 vs. 578.1 ± 491.1) were lower in sEA horses compared with the non-sEA horses (p < 0.01 for each variable). SD2, SDNN, TNN, the SD2/SD1 ratio and Total power showed the greatest discriminatory power in differentiating the sEA and non-sEA groups.
Main limitations: Small sample size.
Conclusion: Our findings indicate that like humans, asthmatic horses show an overall reduction in autonomic control. A relative increase of the parasympathetic modulation of the heart was also observed. After further investigations, HRV measurement might be a non-invasive approach to monitor autonomic nervous system responses of sEA horses.
背景: 马哮喘(EA)严重影响约10%‐15%的马匹。马哮喘EA与人类哮喘非常相似。人类研究通过心率变异性(HRV)分析检测到哮喘患者自主神经系统功能的变化。 研究设计: 观察性研究。 研究目标: 本研究旨在探讨休闲骑乘温血马中，严重马哮喘(sEA)与心率变异性(HRV)之间的关系。 方法: 对20匹被诊断为sEA的马匹和20匹无症状(非sEA)马匹进行调研。调研期间，sEA马匹表现出临床症状且未接受治疗。使用心率(HR)监测仪ECG，在上午9点至11点之间，记录1小时的RR间歇期。使用Kubios软件计算心率变异性数据。根据单因素多元方差分析模型，比较sEA组和非sEA组的记录参数。显著性水平设为α=0.05。 结果: 方差分析显示，sEA马的SD2(mean 99.6±s.d. 25.3 vs. 42.5±17.1)、SDNN(82.7±20.7 vs. 41.3±14.3)、TINN(398.1±104.9 vs. 209.3±71.9)、SD2/SD1比值(1.7±0.2 vs. 1.1±0.3)、TF(4740.2±1977.9 vs. 1503.0±1179.3)、LF(2415.3±1072.4 vs. 707.4±649.9)、SD1(60.9±15.9 vs. 39.2±14.1)、RMSSD(86.0±22.6 vs. 55.3±19.8)和HF(1575.8±902.5 vs. 578.1±491.1)均低于非sEA马(各变量p<0.01)。其中SD2、SDNN、TNN、SD2/SD1比值和TF，在区分sEA和非sEA群体方面，显示出最大的鉴别能力。 主要局限性: 样本量较小。 结论: 本研究结果表明，与人类相似，哮喘马匹的自主神经系统功能整体下降。我们还观察到心脏的副交感调节相对增加。进一步研究后，心率变异性测量可能成为一种无创的监测方法，用于监测sEA马对不同疗法的自主神经系统反应。.
Keywords: autonomic nervous system; equine asthma; heart rate variability; horse.
© 2024 The Author(s). Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.