Document Detail

Bimodal relationship between sinus node arterial distension and sinus nodal automaticity.
MedLine Citation:
PMID:  7282938     Owner:  NLM     Status:  MEDLINE    
In the isolated buffer perfused canine sinus node the effect of either an increase or decrease in perfusion rate (PR), and hence sinus node (SN) arterial pressure (PSNA), on the frequency of sinus nodal depolarization (SDF) is bimodal. SDF decreased from 121.9 +/- 6.1 to 101.4 +/- 6.0 depolarizations/min as PR and PSNA increased from 1 to 4 ml/min and from 18.7 +/- 3.8 to 45.1 +/- 7.3 mmHg, respectively. Further increasing PR from 4 to 10 ml/mn (PSNA increasing from 45.1 +/- 7.3 to 94.0 +/- 14.1 mmHg) caused SDF to increase from 101.4 +/- 6.0 to 121.0 +/- 7.4 depolarizations/min. With respect to the PR, SDF is logarithmically related to the relative degree to which the SN artery is distended, the degree of SN arterial distension being determined by the change in SN arterial resistance (R) with respect to PR (dR/dPR). This relationship is defined by the equation: SDF = 9.23 1n(--dR/dPR) + 99.7. While these results support the existence of a mechanism for autoregulation of sinus nodal automaticity, they indicate that it is considerably more complex than previously envisioned.
G E Musgrave
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Publication Detail:
Type:  In Vitro; Journal Article; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The American journal of physiology     Volume:  241     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1981 Sep 
Date Detail:
Created Date:  1981-11-18     Completed Date:  1981-11-18     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  H311-6     Citation Subset:  IM; S    
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MeSH Terms
Coronary Circulation
Mechanoreceptors / physiology
Myocardial Contraction
Sinoatrial Node / physiology*
Grant Support

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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