Reduced enhancement of high-frequency component in the cross spectrum of ECG and nostril airflow signals in patients with chronic obstructive pulmonary disease

Wan-An Lu; Jane Kuo; Yan-Min Wang; Te-Cheng Lien; Yen-Bin Liu; Jang-Zern Tsai; Cheng-Deng Kuo

doi:10.14814/phy2.12763

Reduced enhancement of high-frequency component in the cross spectrum of ECG and nostril airflow signals in patients with chronic obstructive pulmonary disease

Physiol Rep. 2016 Apr;4(7):e12763. doi: 10.14814/phy2.12763.

Authors

Wan-An Lu¹, Jane Kuo², Yan-Min Wang², Te-Cheng Lien³, Yen-Bin Liu⁴, Jang-Zern Tsai⁵, Cheng-Deng Kuo⁶

Affiliations

¹ Laboratory of Biophysics, Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan Institute of Cultural Asset and Reinvention, Fo-Guang University, Yilan, Taiwan.
² Laboratory of Biophysics, Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan.
³ Division of Respiratory Therapy, Department of Chest Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
⁴ Medical Department, National Taiwan University Hospital, Taipei, Taiwan.
⁵ Department of Electrical Engineering, National Central University, Jung-Li City, Taiwan.
⁶ Laboratory of Biophysics, Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan Division of Respiratory Therapy, Department of Chest Medicine, Taipei Veterans General Hospital, Taipei, Taiwan cdkuo23@gmail.com.

Abstract

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.

Keywords: Body mass index; chronic obstructive pulmonary disease; cross‐spectral analysis; electrocardiogram; heart rate variability; respiration.

Publication types

Observational Study
Research Support, Non-U.S. Gov't

MeSH terms

Aged
Aged, 80 and over
Airway Resistance*
Case-Control Studies
Electrocardiography*
Female
Forced Expiratory Volume
Fourier Analysis
Heart Rate*
Humans
Male
Nose / physiopathology*
Predictive Value of Tests
Prospective Studies
Pulmonary Disease, Chronic Obstructive / diagnosis
Pulmonary Disease, Chronic Obstructive / physiopathology*
Respiration*
Respiratory Rate
Signal Processing, Computer-Assisted*
Time Factors
Vital Capacity