Document Detail


Further information from a sonometric study of the normal tricuspid valve annulus in sheep: geometric changes during the cardiac cycle.
MedLine Citation:
PMID:  17944124     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND AND AIM OF THE STUDY: In a previous sono-metric study, changes were described that occurred in the normal tricuspid valve during the cardiac cycle. However, the wealth of data available suggested the need for reporting further findings that should contribute to a better understanding of the dynamics of the tricuspid valve. METHODS: Thirteen sonomicrometry transducers were placed in the hearts of each of seven sheep. Six transducers were placed in the tricuspid annulus (TA), at the base of each leaflet, and at each commissure; three at the tips of the papillary muscles (PMs); three in the free edges of the leaflets; and one transducer was placed at the apex. Distances between transducers, pulmonary and right ventricular pressures, and pulmonary flow were recorded simultaneously. RESULTS: The TA area underwent two major contractions and expansions during the cardiac cycle, reaching its maximum during isovolumic relaxation and its minimum in diastole. The TA height-to-width ratio changed from 8.4 +/- 1.9% to 15.3 +/- 4.2%. The leaflets began to open before end-systole. By the end of isovolumic relaxation, the leaflets had completed 54.1 +/- 13.4% of their opening. The PM and TA planes were not parallel, but were offset by 11.5 +/- 1.9 degrees to 17.8 +/- 2.1 degrees. The PM rotated 6.9 +/- 0.9 degrees with respect to the TA, with 3.1 +/- 1.1 degrees of the rotation occurring during ejection. CONCLUSION: The tricuspid valve is not a passive structure but rather forms a dynamic part of the right ventricle. Its orifice area changes not only due to the contraction and expansion of its perimeter but also to changes in its saddle shape. Leaflet opening and closure is not simply a response to pressure. The PMs rotate in relation to the TA. These data should impact upon the diagnosis and surgery of functional tricuspid regurgitation.
Authors:
Jerome Jouan; Matthew R Pagel; Matthew E Hiro; Khee Hiang Lim; Emmanuel Lansac; Carlos M G Duran
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  The Journal of heart valve disease     Volume:  16     ISSN:  0966-8519     ISO Abbreviation:  J. Heart Valve Dis.     Publication Date:  2007 Sep 
Date Detail:
Created Date:  2007-10-19     Completed Date:  2008-02-14     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  9312096     Medline TA:  J Heart Valve Dis     Country:  England    
Other Details:
Languages:  eng     Pagination:  511-8     Citation Subset:  IM    
Affiliation:
The International Heart Institute of Montana Foundation at St. Patrick Hospital and Health Sciences Center and The University of Montana, Missoula, Montana 59802, USA.
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MeSH Terms
Descriptor/Qualifier:
Animals
Blood Circulation / physiology*
Blood Pressure / physiology
Cardiac Output / physiology
Cardiovascular Physiological Phenomena*
Heart Rate / physiology
Sheep
Stroke Volume / physiology
Tricuspid Valve / physiology*,  ultrasonography*
Tricuspid Valve Insufficiency / physiopathology,  surgery
Ventricular Function, Right / physiology

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


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