Abstract：
BACKGROUND: The interaction between the cardiovascular and respiratory systems in healthy subjects is determined by the autonomic nervous system and reflected in respiratory sinus arrhythmia. Recently, another pattern of cardio-respiratory coupling (CRC) has been proposed linking synchronization of heart and respiratory system. However, CRC has not been studied precisely in heart failure (HF) with reduced ejection fraction (EF) (HFrEF) according to the myocardial recovery.
METHODS: 10-min resting electrocardiography measurements were performed in persistent HFrEF patients (n=40) who had a subsequent left ventricular EF (LVEF) of ≤ 40 %, HF with recovered EF patients (HFrecEF) (n=41) who had a subsequent LVEF of > 40 % and healthy controls (n=40). Respiratory frequency, respiratory rate, CRC index, time-domain, frequency-domain and nonlinear heart rate variability indices were obtained using standardized software-Kubios™. CRC index was defined as respiratory high-frequency peak minus heart rate variability high-frequency peak.
RESULTS: Respiratory rate was positively correlated with high-frequency (HF) peak (Hz) in both persistent HFrEF group (p<0.001) and HFrecEF group (p<0.001), while respiratory rate was negatively correlated with HF power (ms2) in the healthy controls (p<0.05). CRC index was lowest in the persistent HFrEF group followed by HFrecEF and was high in healthy controls (0.008 vs 0.012 vs 0.056 Hz, p=0.03).
CONCLUSIONS: CRC index was lowest in patients with impaired myocardial recovery, which indicates that cardio-respiratory synchrony is stronger in persistent HFrEF. This may represent a higher HF peak (Hz)/lower HF power (ms2) and abnormal sympathovagal balance in persistent HFrEF group compared to healthy controls. Further work is underway to tests this hypothesis and determine the utility of CRC index in HF phenotypes and its utility as a potential biomarker of response with neuromodulation.
METHODS: 10-min resting electrocardiography measurements were performed in persistent HFrEF patients (n=40) who had a subsequent left ventricular EF (LVEF) of ≤ 40 %, HF with recovered EF patients (HFrecEF) (n=41) who had a subsequent LVEF of > 40 % and healthy controls (n=40). Respiratory frequency, respiratory rate, CRC index, time-domain, frequency-domain and nonlinear heart rate variability indices were obtained using standardized software-Kubios™. CRC index was defined as respiratory high-frequency peak minus heart rate variability high-frequency peak.
RESULTS: Respiratory rate was positively correlated with high-frequency (HF) peak (Hz) in both persistent HFrEF group (p<0.001) and HFrecEF group (p<0.001), while respiratory rate was negatively correlated with HF power (ms2) in the healthy controls (p<0.05). CRC index was lowest in the persistent HFrEF group followed by HFrecEF and was high in healthy controls (0.008 vs 0.012 vs 0.056 Hz, p=0.03).
CONCLUSIONS: CRC index was lowest in patients with impaired myocardial recovery, which indicates that cardio-respiratory synchrony is stronger in persistent HFrEF. This may represent a higher HF peak (Hz)/lower HF power (ms2) and abnormal sympathovagal balance in persistent HFrEF group compared to healthy controls. Further work is underway to tests this hypothesis and determine the utility of CRC index in HF phenotypes and its utility as a potential biomarker of response with neuromodulation.
摘要：
背景：健康受试者的心血管和呼吸系统之间的相互作用由自主神经系统决定，并反映在呼吸窦性心律失常中。最近,已经提出了连接心脏和呼吸系统同步的另一种心肺耦合(CRC)模式。然而,根据心肌恢复情况，尚未在射血分数（EF）（HFrEF）降低的心力衰竭（HF）中精确研究CRC。
方法：对随后左心室EF（LVEF）≤40％的持续性HFrEF患者（n=40）进行10分钟静息心电图测量，HF与恢复的EF患者（HFrecEF）（n=41），其随后的LVEF>40％和健康对照（n=40）。呼吸频率,呼吸频率,CRC索引,时域,使用标准化软件KubiosTM获得频域和非线性心率变异性指数。CRC指数定义为呼吸高频峰值减去心率变异性高频峰值。
结果：在持续性HFrEF组（p<0.001）和HFrecEF组（p<0.001）中，呼吸频率与高频（HF）峰值（Hz）呈正相关，健康对照组呼吸频率与HF功率（ms2）呈负相关（p<0.05）。CRC指数在持续性HFrEF组最低，其次是HFrecEF，在健康对照组中很高（0.008vs0.012vs0.056Hz，p=0.03)。
结论：心肌恢复受损患者的CRC指数最低，这表明持续HFrEF的心肺同步性更强。与健康对照相比，这可能代表持续性HFrEF组中较高的HF峰值（Hz）/较低的HF功率（ms2）和异常的交感神经平衡。正在进行进一步的工作以测试该假设并确定CRC指数在HF表型中的实用性及其作为神经调节反应的潜在生物标志物的实用性。
方法：对随后左心室EF（LVEF）≤40％的持续性HFrEF患者（n=40）进行10分钟静息心电图测量，HF与恢复的EF患者（HFrecEF）（n=41），其随后的LVEF>40％和健康对照（n=40）。呼吸频率,呼吸频率,CRC索引,时域,使用标准化软件KubiosTM获得频域和非线性心率变异性指数。CRC指数定义为呼吸高频峰值减去心率变异性高频峰值。
结果：在持续性HFrEF组（p<0.001）和HFrecEF组（p<0.001）中，呼吸频率与高频（HF）峰值（Hz）呈正相关，健康对照组呼吸频率与HF功率（ms2）呈负相关（p<0.05）。CRC指数在持续性HFrEF组最低，其次是HFrecEF，在健康对照组中很高（0.008vs0.012vs0.056Hz，p=0.03)。
结论：心肌恢复受损患者的CRC指数最低，这表明持续HFrEF的心肺同步性更强。与健康对照相比，这可能代表持续性HFrEF组中较高的HF峰值（Hz）/较低的HF功率（ms2）和异常的交感神经平衡。正在进行进一步的工作以测试该假设并确定CRC指数在HF表型中的实用性及其作为神经调节反应的潜在生物标志物的实用性。
