Document Detail

Nonlinear mechanics of the heart's swinging during pericardial effusion.
MedLine Citation:
PMID:  2801988     Owner:  NLM     Status:  MEDLINE    
When excessive fluid accumulates in the pericardial space, the heart, suspended by the great vessels, is then free to swing as a pendulum. The swinging may occur at either the same frequency as the heart rate (1:1 oscillation) or at half the heart rate (2:1 oscillation), the latter frequency often arising during cardiac tamponade. We show that these two frequencies of oscillation may be explained by the nonlinearity of Newton's equation of motion as applied to the heart. Terms in the equation correspond to gravitational and buoyancy forces, forces due to ejection of blood into the great vessels, and damping forces. A transition between the 1:1 and 2:1 swinging is found to occur when particular parameters of the model are changed, notably when there is an increase of heart rate. This finding is compatible with previous clinical reports.
D R Rigney; A L Goldberger
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; 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:  257     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1989 Oct 
Date Detail:
Created Date:  1989-11-17     Completed Date:  1989-11-17     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:  H1292-305     Citation Subset:  IM; S    
Department of Medicine, Beth Israel Hospital, Boston, Massachusetts.
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MeSH Terms
Heart / anatomy & histology,  physiopathology*
Heart Rate
Models, Cardiovascular*
Pericardial Effusion / physiopathology*
Grant Support

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

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