Document Detail


Effects of annular size, transmitral pressure, and mitral flow rate on the edge-to-edge repair: an in vitro study.
MedLine Citation:
PMID:  16996934     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Although edge-to-edge repair is an established adjunctive procedure, there is still debate on its long-term durability and efficacy. METHODS: Fifteen porcine mitral valves were studied in a physiologic left heart simulator with a variable size annulus (dilated = 8.22 cm2, normal = 6.86 cm2, contracted = 5.5 cm2). Mitral valves were tested under steady and physiologic pulsatile flow conditions (cardiac outputs: 4 to 6 L/min), at peak transmitral pressures between 100 mm Hg and 140 mm Hg. A miniature force transducer was used to measure the Alfieri stitch force (F(A)). Mitral flow rate (MFR), transmitral pressure, effective orifice area, mitral regurgitation, and F(A) were monitored. RESULTS: The edge-to-edge repair led to a decrease in effective orifice area of 16.55% +/- 8.22%; further reduction in effective orifice area was attained with annular contraction. Mitral regurgitation after the edge-to-edge repair was significantly higher (p <0.05) with annular dilation. In the pulsatile experiments, two peaks in F(A) were observed: one during systole (F(A) = 0.059 +/- 0.024 N) and a second during diastole (F(A) = 0.072 +/- 0.021 N). Multivariate analysis of variance analysis showed that during systole, transmitral pressure and mitral annular area (MAA) had significant effects on F(A) [F(A) = (4.40 x 10(-4)) transmitral pressure (mm Hg) + (5.0 x 10(-3)) MAA (cm2) - 0.05 (R2 = 0.80)], whereas during diastole MFR and MAA had significant effects on F(A) [F(A) = (1.03 x 10(-4)) MFR2 (L/min) - (1.60 x 10(-3)) MAA (cm2) + 0.02 (R2 = 0.90)]. CONCLUSIONS: With annular dilation, mitral regurgitation persisted even after the edge-to-edge repair. The edge-to-edge repair does not cause clinically relevant mitral valve stenosis in a normal size mitral valve. Mitral flow rate and transmitral pressure are the main determinants of F(A) during the cardiac cycle. Increasing annular area increases F(A) during systole but decreases F(A) during diastole. Systolic F(A) may become dominant with increases in MAA or peak transmitral pressure, or both.
Authors:
Jorge H Jimenez; Joseph Forbess; Laura R Croft; Lisa Small; Zhaoming He; Ajit P Yoganathan
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Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural    
Journal Detail:
Title:  The Annals of thoracic surgery     Volume:  82     ISSN:  1552-6259     ISO Abbreviation:  Ann. Thorac. Surg.     Publication Date:  2006 Oct 
Date Detail:
Created Date:  2006-09-25     Completed Date:  2006-10-17     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  15030100R     Medline TA:  Ann Thorac Surg     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  1362-8     Citation Subset:  AIM; IM    
Affiliation:
Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0535, USA.
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MeSH Terms
Descriptor/Qualifier:
Animals
Blood Pressure
Body Weights and Measures
Cardiac Surgical Procedures / methods*
Cardiomyopathy, Dilated / complications,  physiopathology
Disease Models, Animal
Heart / physiology,  physiopathology
Hemodynamics
Mitral Valve / physiopathology*
Mitral Valve Insufficiency / etiology,  physiopathology,  surgery*
Models, Animal
Models, Cardiovascular
Pulsatile Flow
Regional Blood Flow
Swine
Ventricular Remodeling / physiology
Grant Support
ID/Acronym/Agency:
HL52009/HL/NHLBI NIH HHS

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


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