Next Article in Journal
Analyses of the Instabilities in the Discretized Diffusion Equations via Information Theory
Next Article in Special Issue
Fatiguing Effects on the Multi-Scale Entropy of Surface Electromyography in Children with Cerebral Palsy
Previous Article in Journal
Heat Transfer Enhancement and Entropy Generation of Nanofluids Laminar Convection in Microchannels with Flow Control Devices
Previous Article in Special Issue
Complexity Analysis of Surface EMG for Overcoming ECG Interference toward Proportional Myoelectric Control
Article Menu

Export Article

Open AccessArticle
Entropy 2016, 18(4), 153; doi:10.3390/e18040153

Measuring Electromechanical Coupling in Patients with Coronary Artery Disease and Healthy Subjects

1
School of Control Science and Engineering, Shandong University, Jingshi Road 17923, Jinan 250061, China
2
School of Computer Science and Technology, Shandong University, Shunhua Road 1500, Jinan 250101, China
*
Authors to whom correspondence should be addressed.
Academic Editor: Raúl Alcaraz Martínez
Received: 21 January 2016 / Revised: 7 April 2016 / Accepted: 15 April 2016 / Published: 21 April 2016
View Full-Text   |   Download PDF [2236 KB, uploaded 21 April 2016]   |  

Abstract

Coronary artery disease (CAD) is the most common cause of death globally. To detect CAD noninvasively at an early stage before clinical symptoms occur is still nowadays challenging. Analysis of the variation of heartbeat interval (RRI) opens a new avenue for evaluating the functional change of cardiovascular system which is accepted to occur at the subclinical stage of CAD. In addition, systolic time interval (STI) and diastolic time interval (DTI) also show potential. There may be coupling in these electromechanical time series due to their physiological connection. However, to the best of our knowledge no publication has systematically investigated how can the coupling be measured and how it changes in CAD patients. In this study, we enrolled 39 CAD patients and 36 healthy subjects and for each subject the electrocardiogram (ECG) and photoplethysmography (PPG) signals were recorded simultaneously for 5 min. The RRI series, STI series, and DTI series were constructed, respectively. We used linear cross correlation (CC), coherence function (CF), as well as nonlinear mutual information (MI), cross conditional entropy (XCE), cross sample entropy (XSampEn), and cross fuzzy entropy (XFuzzyEn) to analyse the bivariate RRI-DTI coupling, RRI-STI coupling, and STI-DTI coupling, respectively. Our results suggest that the linear CC and CF generally have no significant difference between the two groups for all three types of bivariate coupling. The MI only shows weak change in RRI-DTI coupling. By comparison, the three entropy-based coupling measurements show significantly decreased coupling in CAD patients except XSampEn for RRI-DTI coupling (less significant) and XCE for STI-DTI and RRI-STI coupling (not significant). Additionally, the XFuzzyEn performs best as it was still significant if we further applied the Bonferroni correction in our statistical analysis. Our study indicates that the intrinsic electromechanical coupling is most probably nonlinear and can better be measured by nonlinear entropy-based measurements especially the XFuzzyEn. Besides, CAD patients are accompanied by a loss of electromechanical coupling. Our results suggest that cardiac electromechanical coupling may potentially serve as a noninvasive diagnostic tool for CAD. View Full-Text
Keywords: coronary artery disease; coupling; entropy-based measurement; electrocardiogram; photoplethysmography; heartbeat interval; diastolic time interval; systolic time interval coronary artery disease; coupling; entropy-based measurement; electrocardiogram; photoplethysmography; heartbeat interval; diastolic time interval; systolic time interval
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Supplementary material

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Ji, L.; Li, P.; Liu, C.; Wang, X.; Yang, J.; Liu, C. Measuring Electromechanical Coupling in Patients with Coronary Artery Disease and Healthy Subjects. Entropy 2016, 18, 153.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Entropy EISSN 1099-4300 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top