Document Detail


Left ventricular dynamic geometry and diastolic mechanics in a model of chronic cyanosis and right ventricular pressure overload.
MedLine Citation:
PMID:  7464199     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Left ventricular (LV) mechanics and dynamic geometry were studied in eight dogs 1 to 151 days after creation of a model of cyanosis and increased right ventricular (RV) pressure. In each dog, an 8 mm conduit was interposed between the main pulmonary artery and left atrium; the pulmonary artery was then banded distal to this shunt. Ultrasonic dimension transducers were subsequently implanted for the measurement of LV equatorial minor axis and wall thickness. Catheter-tipped micromanometers were used to measure LV and pleural pressures; RV pressure was measured with a fluid-filled catheter and an external transducer. Eight control animals were similarly instrumented. At the time of study, the cyanotic dogs had significantly decreased arterial oxygen saturations (66% +/- 7% versus controls: 96% +/- 5%), significantly elevated peak RV pressures, (55 +/- 7 mm Hg versus controls: 30 +/- 5 mm Hg) and significantly elevated ratios of RV to LV mass (0.52 +/- 0.05 versus controls: 0.36 +/- 0.05). Diastolic pressure-dimension curves were generated and time constant for LV relaxation were calculated for each animal. The diastolic curves obtained from the cyanotic dogs were not significantly different from those of the control animals, and LV relaxation was not prolonged in the cyanotic dogs. In the three dogs that were cyanotic for 4 months or longer, there was a profound abnormality in the geometric pattern of LV contraction, manifested by asynchronous shortening of the anteroposterior equatorial minor axis. In two of these three dogs, inotropic reserves were assessed by means of postextrasystolic potentiation and were found to be normal. The results of this study indicate that short-term mild cyanosis and RV pressure overload do not alter diastolic compliance nor prolong relaxation of the LV. LV dynamic geometry may become abnormal after 4 months, with preservation of global LV inotropic reserves.
Authors:
M S Visner; C E Arentzen; W S Ring; R W Anderson
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The Journal of thoracic and cardiovascular surgery     Volume:  81     ISSN:  0022-5223     ISO Abbreviation:  J. Thorac. Cardiovasc. Surg.     Publication Date:  1981 Mar 
Date Detail:
Created Date:  1981-04-24     Completed Date:  1981-04-24     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0376343     Medline TA:  J Thorac Cardiovasc Surg     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  347-57     Citation Subset:  AIM; IM    
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MeSH Terms
Descriptor/Qualifier:
Animals
Cyanosis / physiopathology*
Diastole*
Disease Models, Animal
Dogs
Heart Defects, Congenital / physiopathology*
Heart Ventricles / physiopathology*
Myocardial Contraction*
Oxygen / blood
Time Factors
Grant Support
ID/Acronym/Agency:
HL05704/HL/NHLBI NIH HHS; HL05759/HL/NHLBI NIH HHS; HL22152/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
7782-44-7/Oxygen

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


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