Department of Thoracic Medicine, Chang Gung Memorial Hospital, 199 Tun-Hwa N. Rd., Taipei, Taiwan.
College of Medicine, Chang Gung University, Taoyuan, Taiwan.
BMC Pulm Med. 2021 Jan 12;21(1):22. doi: 10.1186/s12890-021-01400-1.
The interaction between the pulmonary function and cardiovascular mechanics is a crucial issue, particularly when treating patients with chronic obstructive pulmonary disease (COPD). Synchrogram index is a new parameter that can quantify this interaction and has the potential to apply in COPD patients. Our objective in this study was to characterize cardiorespiratory interactions in terms of cardiorespiratory coupling (CRC) using the synchrogram index of the heart rate and respiratory flow signals in patients with chronic obstructive pulmonary disease.
This is a cross-sectional and preliminary data from a prospective study, which examines 55 COPD patients. K-means clustering analysis was applied to cluster COPD patients based on the synchrogram index. Linear regression and multivariable regression analysis were used to determine the correlation between the synchrogram index and the exercise capacity assessed by a six-minute walking test (6MWT).
The 55 COPD patients were separated into a synchronized group (median 0.89 (0.64-0.97), n = 43) and a desynchronized group (median 0.23 (0.02-0.51), n = 12) based on K-means clustering analysis. Synchrogram index was correlated significantly with six minutes walking distance (r = 0.42, p = 0.001) and distance saturation product (r = 0.41, p = 0.001) assessed by 6MWT, and still was an independent variable by multivariable regression analysis.
This is the first result studying the heart-lung interaction in terms of cardiorespiratory coupling in COPD patients by the synchrogram index, and COPD patients are clustered into synchronized and desynchronized groups. Cardiorespiratory coupling is associated with exercise capacity in patients with COPD.
肺功能和心血管力学之间的相互作用是一个关键问题，特别是在治疗慢性阻塞性肺疾病（COPD）患者时。同步图指数是一种新的参数，可以量化这种相互作用，并有可能应用于 COPD 患者。我们的目的是使用心率和呼吸流量信号的同步图指数来描述 COPD 患者的心肺相互作用。
这是一项横断面和前瞻性研究的初步数据，检查了 55 例 COPD 患者。应用 K-均值聚类分析根据同步图指数对 COPD 患者进行聚类。线性回归和多变量回归分析用于确定同步图指数与六分钟步行试验（6MWT）评估的运动能力之间的相关性。
根据 K-均值聚类分析，55 例 COPD 患者分为同步组（中位数 0.89（0.64-0.97），n=43）和不同步组（中位数 0.23（0.02-0.51），n=12）。同步图指数与 6MWT 评估的六分钟步行距离（r=0.42，p=0.001）和距离饱和乘积（r=0.41，p=0.001）显著相关，并且通过多变量回归分析仍然是一个独立变量。
这是第一项使用同步图指数研究 COPD 患者心肺耦联的心肺相互作用的研究结果，并将 COPD 患者聚类为同步组和不同步组。心肺耦联与 COPD 患者的运动能力相关。
