Document Detail


Left ventricular pressure-volume loop analysis during continuous cardiac assist in acute animal trials.
MedLine Citation:
PMID:  17470206     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
For better understanding of the interaction between left ventricle and continuous cardiac assist, the effect of different working conditions and support levels on left ventricular pressure-volume (PV) loop was investigated in acute animal experiments. A MicroMed-DeBakey ventricular assist device (MicroMed Cardiovascular Inc., Houston, TX, USA) was implanted in seven healthy sheep (102 +/- 20 kg). Measurements of hemodynamic variables were taken with clamped graft, on minimum, medium, and maximum support, and in pump-off condition (backflow). Each pump condition was studied for different heart rates, central venous pressures, and under pharmacologically altered contractility. End-systolic and end-diastolic volume normalized by the body surface area (BSA) (end systolic volume index [ESVI] and end diastolic volume index [EDVI]) showed significant correlation both within each sheep and in the pooled data. The linear regression for the pooled data was ESVI = 0.845 x EDVI - 15.21, R(2) = 0.924, P < 0.0001, n = 200. EDVI and stroke volume (SV) normalized by BSA (stroke volume index [SVI]) also showed a lower but significant correlation: SVI = 0.155 x EDVI + 15.21, R(2) = 0.291, P < 0.0001, n = 200. An increase of preload due to infusion caused, in the clamped graft condition, an increase in end diastolic volume of 22%, no significant increase in SV, a decrease both of systemic vascular resistance of 30% and ventricular contractility (maximum elastance [E(max)] and peak rate of rise of ventricular pressure [dP/dt(max)] decreasing 38 and 21%, respectively). PV loop analysis in continuous cardiac assist reveals that the ESVI and the EDVI are strongly correlated and that ESVI varies considerably with preload. SVI becomes slightly dependent on EDVI, which may be due to autoregulatory mechanisms.
Authors:
Francesco Moscato; Michael Vollkron; Helga Bergmeister; Georg Wieselthaler; Edward Leonard; Heinrich Schima
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Artificial organs     Volume:  31     ISSN:  0160-564X     ISO Abbreviation:  Artif Organs     Publication Date:  2007 May 
Date Detail:
Created Date:  2007-05-01     Completed Date:  2007-07-19     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7802778     Medline TA:  Artif Organs     Country:  United States    
Other Details:
Languages:  eng     Pagination:  369-76     Citation Subset:  IM    
Affiliation:
Department of Biomedical Engineering and Physics, Medical University of Vienna, Vienna, Austria.
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MeSH Terms
Descriptor/Qualifier:
Acute Disease
Animals
Disease Models, Animal
Heart / physiology*
Heart-Assist Devices*
Sheep
Stroke Volume / physiology*
Ventricular Function, Left / physiology*

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