Cardiovascular section, Department of medicine, University of Oklahoma Health Science Center, OK, USA.
Cardiovascular section, Department of medicine, University of Oklahoma Health Science Center, OK, USA.
Respir Physiol Neurobiol. 2024 Oct;328:104313. doi: 10.1016/j.resp.2024.104313. Epub 2024 Aug 8.
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.
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.
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 (ms) 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).
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 (ms) 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.
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，提出了另一种心脏-呼吸偶联（CRC）模式，该模式将心脏和呼吸系统的同步联系起来。然而，根据心肌恢复情况，尚未在射血分数降低的心力衰竭（HFrEF）（HFrecEF）中对 CRC 进行精确研究。
对持续性 HFrEF 患者（n=40）进行了 10 分钟的静息心电图测量，这些患者随后的左心室射血分数（LVEF）≤40%；HFrecEF 患者（n=41）随后的 LVEF > 40%；健康对照组（n=40）。使用标准化软件-Kubios™ 获得呼吸频率、呼吸率、CRC 指数、时域、频域和非线性心率变异性指数。CRC 指数定义为呼吸高频峰减去心率变异性高频峰。
呼吸率与持续性 HFrEF 组（p<0.001）和 HFrecEF 组（p<0.001）的高频（HF）峰值（Hz）均呈正相关，而呼吸率与健康对照组的 HF 功率（ms）呈负相关（p<0.05）。CRC 指数在持续性 HFrEF 组最低，其次是 HFrecEF 组，在健康对照组中最高（0.008 对 0.012 对 0.056 Hz，p=0.03）。
在心肌恢复受损的患者中，CRC 指数最低，这表明在持续性 HFrEF 中，心肺同步性更强。这可能代表持续性 HFrEF 组的 HF 峰值（Hz）/HF 功率（ms）较低，以及交感神经-迷走神经平衡异常，与健康对照组相比。正在进行进一步的工作来检验这一假设，并确定 CRC 指数在 HF 表型中的效用及其作为神经调节反应潜在生物标志物的效用。
