Investigation of the influence of swallowing, coughing and vocalization on heart rate variability with respiratory-phase domain analysis.
OBJECTIVE
The objective of our study is to investigate extrinsic influences on heart rate variability using respiratory-phase domain analysis. Swallowing, coughing and vocalization (reading aloud and conversation) are adopted as extrinsic influences.


METHODS
In this study, an instantaneous R-R interval (RRI) is sampled at each pi/10 rad of the respiratory phase and the data is divided into three subsets: a) respiration with event, b) one respiration after the event, and c) normal respiration. Then the mean waveforms of respiratory sinus arrhythmia (RSA) are calculated and compared.


CONCLUSIONS
It is found that swallowing induces tachycardia that recovers within one respiration. Coughing also induces tachycardia, but it does not recover within one respiration. Vocalization shortens the mean RRI, but the changing respiratory pattern due to vocalization has no statistically significant influence on the amplitude of RSA. Furthermore, it is found that the proposed method is effective for analyzing extrinsic influences on heart rate variability (HRV).
Kotani
K
K
Graduate School of Information Science and Technology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan. kota@nano.pe.u-tokyo.ac.jp
Tachibana
M
M
Takamasu
K
K
D000465:Algorithms; D003371:Cough; D003679:Deglutition / Q000502:physiology*; D003680:Deglutition Disorders; D004562:Electrocardiography; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D011597:Psychomotor Performance / Q000502:physiology; D015656:Respiratory Mechanics / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted; D015398:Signal Transduction; D013060:Speech / Q000502:physiology*; D013610:Tachycardia / Q000503:physiopathology; D013995:Time; D013997:Time Factors