Document Detail


Left ventricular epicardial admittance measurement for detection of acute LV dilation.
MedLine Citation:
PMID:  21148342     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
There are two implanted heart failure warning systems incorporated into biventricular pacemakers/automatic implantable cardiac defibrillators and tested in clinical trials: right heart pressures, and lung conductance measurements. However, both warning systems postdate measures of the earliest indicator of impending heart failure: left ventricular (LV) volume. There are currently no proposed implanted technologies that can perform LV blood volume measurements in humans. We propose to solve this problem by incorporating an admittance measurement system onto currently deployed biventricular and automatic implantable cardiac defibrillator leads. This study will demonstrate that an admittance measurement system can detect LV blood conductance from the epicardial position, despite the current generating and sensing electrodes being in constant motion with the heart, and with dynamic removal of the myocardial component of the returning voltage signal. Specifically, in 11 pigs, it will be demonstrated that 1) a physiological LV blood conductance signal can be derived; 2) LV dilation in response to dose-response intravenous neosynephrine can be detected by blood conductance in a similar fashion to the standard of endocardial crystals when admittance is used, but not when only traditional conductance is used; 3) the physiological impact of acute left anterior descending coronary artery occlusion and resultant LV dilation can be detected by blood conductance, before the anticipated secondary rise in right ventricular systolic pressure; and 4) a pleural effusion simulated by placing saline outside the pericardium does not serve as a source of artifact for blood conductance measurements.
Authors:
John E Porterfield; Erik R Larson; James T Jenkins; Daniel Escobedo; Jonathan W Valvano; John A Pearce; Marc D Feldman
Publication Detail:
Type:  Evaluation Studies; Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2010-12-09
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  110     ISSN:  1522-1601     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2011 Mar 
Date Detail:
Created Date:  2011-03-09     Completed Date:  2011-07-07     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  United States    
Other Details:
Languages:  eng     Pagination:  799-806     Citation Subset:  IM    
Affiliation:
Univ. of Texas at Austin, USA.
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MeSH Terms
Descriptor/Qualifier:
Animals
Diagnosis, Computer-Assisted / methods*
Electric Impedance / diagnostic use
Heart Ventricles / physiopathology*
Hypertrophy, Left Ventricular / diagnosis*,  physiopathology*
Plethysmography, Impedance / methods*
Reproducibility of Results
Sensitivity and Specificity
Stroke Volume*
Swine
Grant Support
ID/Acronym/Agency:
R21 HL 079926/HL/NHLBI NIH HHS; UL 1RR025767/RR/NCRR NIH HHS; UL1 RR025767/RR/NCRR NIH HHS; UL1 TR000149/TR/NCATS NIH HHS
Comments/Corrections

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