Respiratory sinus arrhythmia in conscious humans during spontaneous respiration.
Summary of "Respiratory sinus arrhythmia in conscious humans during spontaneous respiration."
Respiratory sinus arrhythmia (RSA) is the beat-to-beat fluctuation in heart rate at the frequency of the respiratory cycle. While it is common to study RSA under conditions of controlled breathing, where respiratory frequency, and sometimes tidal volume and inspiratory:expiratory ratio are controlled, the effect of controlled breathing on RSA is not clear. While not all studies exploring the effects of controlled breathing on RSA magnitude are consistent, some of the best-designed studies addressing this question did find a significant effect. In addition to respiratory timing influencing heartbeats, there is evidence that cardiac timing also influences respiratory timing, termed cardioventilatory coupling. Thus, the timing interactions between the cardiac and respiratory systems are complex, and bi-directional. Controlled breathing eliminates one aspect of this relationship, and studies designed to understand cardiorespiratory physiology conducted under these conditions need to be interpreted with an understanding that they may not represent normal physiology.
Affiliation
Department of Surgery and Anaesthesia, University of Otago, Wellington, Wellington South, New Zealand. Peter.larsen@otago.ac.nz
Journal Details
This article was published in the following journal.
Name: Respiratory physiology & neurobiology
ISSN: 1878-1519
Pages: 111-8
Links
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/20420940
- DOI: http://dx.doi.org/10.1016/j.resp.2010.04.021
Medical and Biotech [MESH] Definitions
Arrhythmia, Sinus
Irregular HEART RATE caused by abnormal function of the SINOATRIAL NODE. It is characterized by a greater than 10% change between the maximum and the minimum sinus cycle length or 120 milliseconds.
Respiration Disorders
Diseases of the respiratory system in general or unspecified or for a specific respiratory disease not available.
Apnea
A transient absence of spontaneous respiration.
Carotid-cavernous Sinus Fistula
An acquired or spontaneous abnormality in which there is communication between CAVERNOUS SINUS, a venous structure, and the CAROTID ARTERIES. It is often associated with HEAD TRAUMA, specifically basilar skull fractures (SKULL FRACTURE, BASILAR). Clinical signs often include VISION DISORDERS and INTRACRANIAL HYPERTENSION.
Paranasal Sinuses
Air-filled spaces located within the bones around the NASAL CAVITY. They are extensions of the nasal cavity and lined by the ciliated NASAL MUCOSA. Each sinus is named for the cranial bone in which it is located, such as the ETHMOID SINUS; the FRONTAL SINUS; the MAXILLARY SINUS; and the SPHENOID SINUS.
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