Interferences between baroreflex and respiration. Evaluation by symbolic analysis and conditional entropy.
BACKGROUND
The baroreflex is one of the most important short-term cardiovascular autonomic control mechanisms. Its interactions with other reflexes, mainly cardiopulmonary reflexes, are of paramount importance in controlling heart rate.


OBJECTIVE
This study assesses the coupling between baroreflex and respiration during a progressive bicycle mild dynamical exercise.


METHODS
The coupling was assessed by symbolic analysis and conditional entropy.


RESULTS
Findings suggested the close relationship between the baroreflex sequences and the phase of respiratory signal and, thus, the interference between baroreflex and cardiopulmonary reflexes.


CONCLUSIONS
Indexes describing baroreflex based on spontaneous variability are strongly affected by cardiopulmonary influences.
Vallais
F
F
Dipartimento di Bioingegneria, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milano, Italy.
Porta
A
A
Lucini
D
D
Pagani
M
M
Aletti
F
F
Baselli
G
G
D000328:Adult; D017704:Baroreflex / Q000502:physiology*; D001642:Bicycling / Q000502:physiology; D003626:Data Display; D004562:Electrocardiography; D019277:Entropy; D006801:Humans; D010809:Physical Fitness / Q000502:physiology; D010991:Plethysmography; D012016:Reference Values; D012119:Respiration; D012815:Signal Processing, Computer-Assisted; D016683:Supine Position / Q000502:physiology