Document Detail

Cardiogenic oscillations in expired gas: origin and mechanism.
MedLine Citation:
PMID:  6878909     Owner:  NLM     Status:  MEDLINE    
I produced cardiogenic oscillations (C.O.) of gas concentration for Ar, N2 and CO2 in the expirate by inspiration from RV of a bolus of Ar-O2 mixture followed by O2 to TLC. In 3 out of 4 subjects, C.O. of Ar changed phase during expiration by a half cycle with respect to C.O. of CO2, as was predicted by a previously suggested model (Arieli, R., A.J. Olszowka and H.D. Van Liew (1981) J. Appl. Physiol. 51: 922-928). The model attributed the production of C.O. to fluctuation of the relative flow from two units which differ from each other in their compliance; and due to an assumed dependence of the resistance on the compliance, the time constant of each lung unit changes as a function of lung volume. By scaling the subject's lung volume to Weibel Model A and by the use of expired volume and ECG, I suggest that the origin of C.O. seen at the mouth is at the terminal bronchioles. I made use of the arrhythmic heart rate of one subject to confirm the aligning of ECG with C.O. and also to show that the volume between the site of C.O. origin and the mouth is a function of lung volume. The differences between C.O. of Ar, N2 and CO2 are attributed to their distribution pattern in the lung.
R Arieli
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Respiration physiology     Volume:  52     ISSN:  0034-5687     ISO Abbreviation:  Respir Physiol     Publication Date:  1983 May 
Date Detail:
Created Date:  1983-09-09     Completed Date:  1983-09-09     Revised Date:  2009-11-11    
Medline Journal Info:
Nlm Unique ID:  0047142     Medline TA:  Respir Physiol     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  191-204     Citation Subset:  IM    
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MeSH Terms
Heart / physiology*
Models, Biological
Grant Support

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