Lu Wan-An, Kuo Jane, Wang Yan-Min, Lien Te-Cheng, Liu Yen-Bin, Tsai Jang-Zern, Kuo Cheng-Deng
Laboratory of Biophysics, Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan Institute of Cultural Asset and Reinvention, Fo-Guang University, Yilan, Taiwan.
Laboratory of Biophysics, Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan.
Physiol Rep. 2016 Apr;4(7). doi: 10.14814/phy2.12763.
Chronic obstructive pulmonary disease (COPD) is a chronic airway disease with increased airway resistance. This study investigated the common characteristics of electrocardiographic (ECG) and nostril airflow signals in COPD patients using cross-spectral analysis. Heart rate variability (HRV) measures and cross-spectral (cs) measures of ECG and nostril airflow were compared in COPD patients and normal subjects, and correlated with their clinical characteristics. We found that cross-spectral analysis can lead to a significant increase in normalized high-frequency power (nHFPcs) and a significant decrease in normalized very low-frequency power (nVLFPcs), normalized low-frequency power (nLFPcs), and low-/high-frequency power ratio (LHRcs) in both normal subjects and COPD patients, as compared with their corresponding HRV measures. Further analysis showed that the percentage increase in nHFP (%nHFP) and the percentage decrease in LHR (%LHR) due to cross-spectral analysis in COPD patients were significantly smaller than those of normal subjects. All cross-spectral measures of ECG and nostril airflow in COPD patients did not significantly correlate with their pulmonary function characteristics. However, the nHFPcs correlated significantly and negatively with body mass index (BMI) in both normal subjects and COPD patients, and the %nHFP correlated significantly and negatively with BMI in COPD patients. We conclude that cross-spectral analysis of ECG and nostril airflow signals could lead to reduced enhancement in the high-frequency component in the cross spectrum of COPD patients. The magnitude of reduced enhancement in the high-frequency component in the cross-spectrum was related to the BMI of the patients. Cross-spectral analysis of ECG and nostril airflow might be used to assess the cardiovascular-related functions of COPD patients.
慢性阻塞性肺疾病（COPD）是一种气道阻力增加的慢性气道疾病。本研究采用互谱分析方法，调查了COPD患者心电图（ECG）和鼻孔气流信号的共同特征。比较了COPD患者和正常受试者的心率变异性（HRV）测量值以及ECG和鼻孔气流的互谱（cs）测量值，并将其与他们的临床特征相关联。我们发现，与相应的HRV测量值相比，互谱分析可导致正常受试者和COPD患者的归一化高频功率（nHFPcs）显著增加，归一化极低频功率（nVLFPcs）、归一化低频功率（nLFPcs）和低频/高频功率比（LHRcs）显著降低。进一步分析表明，COPD患者因互谱分析导致的nHFP增加百分比（%nHFP）和LHR降低百分比（%LHR）显著小于正常受试者。COPD患者的所有ECG和鼻孔气流互谱测量值与他们的肺功能特征均无显著相关性。然而，正常受试者和COPD患者的nHFPcs均与体重指数（BMI）显著负相关，COPD患者的%nHFP与BMI显著负相关。我们得出结论，ECG和鼻孔气流信号的互谱分析可能会导致COPD患者互谱中高频成分的增强减弱。互谱中高频成分增强减弱的程度与患者的BMI有关。ECG和鼻孔气流的互谱分析可能用于评估COPD患者的心血管相关功能。
