| Mechanisms of systemic adaptation to univentricular Fontan conversion. | |
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MedLine Citation:
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PMID: 20483432 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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OBJECTIVE: After univentricular Fontan conversion, systemic venous pressure serves as the sole driving force for transpulmonary blood flow. Consequently, systemic venous return is markedly altered and ventricular filling is subnormal. The mechanisms and time course of systemic adaptation to Fontan conversion are incompletely understood. We hypothesized that acute elevation in systemic venous pressure induces an adaptive response similar to conversion to a univentricular Fontan circulation. METHODS: Adjustable vessel occluders were placed around the superior and inferior vena cavae in juvenile sheep. After 1-week recovery, occluders were tightened to acutely increase and maintain systemic venous pressure at 15 mm Hg (n = 6), simulating 1-stage Fontan conversion. Control animals (n = 4) received identical surgery, but venous pressure was not manipulated. RESULTS: Cardiac index decreased significantly (3.9 ± 1.0 mL/min/m(2) to 2.7 ± 0.7 mL/min/m(2), P < .001) and then normalized to control at 2 weeks. Circulating blood volume increased (100 ± 9.4 mL/kg vs 85.5 ± 8.4 mL/kg, P = .034) as a persistent response. Cardiac reserve improved and was not different from control by week 3. Resting heart rate decreased in both groups. Oxygen extraction (arteriovenous oxygen difference) and neurohormonal mediators increased transiently and then normalized by week 2. CONCLUSIONS: Adaptation to global elevation in systemic venous pressure to Fontan levels is complete within 2 weeks. Increased blood volume and reduced heart rate are persistent responses. Increased oxygen extraction and neurohormonal up-regulation are temporary responses that normalize with recovery of cardiac output. With improved physiologic understanding of systemic adaptation to Fontan conversion, approaches to single-ventricle palliation can be more objectively assessed and optimized. |
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Authors:
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Cynthia D Myers; Kimberly Ballman; Lindsay E Riegle; Kelly D Mattix; Kenneth Litwak; Mark D Rodefeld |
Publication Detail:
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Type: Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't Date: 2010-05-18 |
Journal Detail:
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Title: The Journal of thoracic and cardiovascular surgery Volume: 140 ISSN: 1097-685X ISO Abbreviation: J. Thorac. Cardiovasc. Surg. Publication Date: 2010 Oct |
Date Detail:
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Created Date: 2010-09-20 Completed Date: 2010-10-11 Revised Date: 2012-05-07 |
Medline Journal Info:
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Nlm Unique ID: 0376343 Medline TA: J Thorac Cardiovasc Surg Country: United States |
Other Details:
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Languages: eng Pagination: 850-6, 856.e1-6 Citation Subset: AIM; IM |
Copyright Information:
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Copyright © 2010 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved. |
Affiliation:
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Department of Surgery, Section of Cardiothoracic Surgery, the James Whitcomb Riley Hospital for Children, Indiana University School of Medicine, Indianapolis, Ind, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adaptation, Physiological Animals Blood Volume Cardiac Output Fontan Procedure* Heart Rate Heart Ventricles / physiopathology* Hormones / blood Sheep Time Factors Venous Pressure* Ventricular Function* |
| Grant Support | |
ID/Acronym/Agency:
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C06 RR10601/RR/NCRR NIH HHS; HL080089/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Hormones |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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