Document Detail


Murine Cardiac Catheterizations and Hemodynamics: On the issue of Parallel Conductance.
MedLine Citation:
PMID:  21900070     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
Catheter-based measurements are extensively used nowadays in animal models to quantify global left ventricular (LV) cardiac function and hemodynamics. Conductance catheter measurements yield estimates of left ventricular volumes. Such estimates, however, are confounded by the catheters non-homogeneous emission field and the contribution to the total conductance of surrounding tissue or blood conductance values (other than LV blood), a term often known as parallel conductance. In practice, in most studies, volume estimates are based on the assumptions that the catheters electric field is homogeneous and that parallel conductance is constant, despite prior results showing that these assumptions are incorrect. This study challenges the assumption for spatial homogeneity of electric field excitation of miniature catheters and investigated the electric-field distribution of miniature catheters in the murine heart, based on cardiac modeldriven (geometric, lump component) simulations and non-invasive imaging, at both systolic and diastolic cardiac phases. Results confirm the non-uniform catheter emission field, confined spatially within the LV cavity and myocardium, falling to 10% of its peak value at the ring electrode surface, within 1.1-2.0 mm, given a relative tissue permittivity of 33615. Additionally <1% of power leaks were observed into surrounding cavities or organs at end-diastole. Temporally varying parallel conductance effects are also confirmed, becoming more prominent at end-systole.
Authors:
C Constantinides; S Angeli; R Mean
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2011-9-06
Journal Detail:
Title:  IEEE transactions on bio-medical engineering     Volume:  -     ISSN:  1558-2531     ISO Abbreviation:  -     Publication Date:  2011 Sep 
Date Detail:
Created Date:  2011-9-8     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0012737     Medline TA:  IEEE Trans Biomed Eng     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
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