| Differential modulation of right ventricular strain and right atrial mechanics in mild vs. severe pressure overload. | |
| | |
MedLine Citation:
|
PMID: 21926343 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Increased right atrial (RA) and ventricular (RV) chamber volumes are a late maladaptive response to chronic pulmonary hypertension. The purpose of the current investigation was to characterize the early compensatory changes that occur in the right heart during chronic RV pressure overload before the development of chamber dilation. Magnetic resonance imaging with radiofrequency tissue tagging was performed on dogs at baseline and after 10 wk of pulmonary artery banding to yield either mild RV pressure overload (36% rise in RV pressure; n = 5) or severe overload (250% rise in RV pressure; n = 4). The RV free wall was divided into three segments within a midventricular plane, and circumferential myocardial strain was calculated for each segment, the septum, and the left ventricle. Chamber volumes were calculated from stacked MRI images, and RA mechanics were characterized by calculating the RA reservoir, conduit, and pump contribution to RV filling. With mild RV overload, there were no changes in RV strain or RA function. With severe RV overload, RV circumferential strain diminished by 62% anterior (P = 0.04), 42% inferior (P = 0.03), and 50% in the septum (P = 0.02), with no change in the left ventricle (P = 0.12). RV filling became more dependent on RA conduit function, which increased from 30 ± 9 to 43 ± 13% (P = 0.01), than on RA reservoir function, which decreased from 47 ± 6 to 33 ± 4% (P = 0.04), with no change in RA pump function (P = 0.94). RA and RV volumes and RV ejection fraction were unchanged from baseline during either mild (P > 0.10) or severe RV pressure overload (P > 0.53). In response to severe RV pressure overload, RV myocardial strain is segmentally diminished and RV filling becomes more dependent on RA conduit rather than reservoir function. These compensatory mechanisms of the right heart occur early in chronic RV pressure overload before chamber dilation develops. |
| | |
Authors:
|
Rochus K Voeller; Abdulhameed Aziz; Hersh S Maniar; Nneka N Ufere; Ajay K Taggar; Noel J Bernabe; Brian P Cupps; Marc R Moon |
Related Documents
:
|
21750253 - The impact of lipoic acid on endothelial function and proteinuria in quinapril-treated ... 21885393 - Physiological changes during low- and high-intensity noninvasive ventilation. 11204933 - Effect of calcium antagonists on stress-induced rise in blood pressure and heart rate: ... |
Publication Detail:
|
Type: Comparative Study; Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't Date: 2011-09-16 |
Journal Detail:
|
Title: American journal of physiology. Heart and circulatory physiology Volume: 301 ISSN: 1522-1539 ISO Abbreviation: Am. J. Physiol. Heart Circ. Physiol. Publication Date: 2011 Dec |
Date Detail:
|
Created Date: 2011-12-06 Completed Date: 2012-01-23 Revised Date: 2013-02-19 |
Medline Journal Info:
|
Nlm Unique ID: 100901228 Medline TA: Am J Physiol Heart Circ Physiol Country: United States |
Other Details:
|
Languages: eng Pagination: H2362-71 Citation Subset: IM |
Affiliation:
|
Division of Cardiothoracic Surgery, Washington University School of Medicine, Saint Louis, Missouri, USA. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adaptation, Physiological Animals Atrial Function, Right* Biomechanics Blood Pressure Constriction Disease Models, Animal Dogs Hypertension, Pulmonary / complications*, physiopathology Hypertrophy, Right Ventricular / etiology, physiopathology Magnetic Resonance Imaging Pulmonary Artery / physiopathology, surgery Severity of Illness Index Stress, Mechanical Stroke Volume Time Factors Ventricular Dysfunction, Right / etiology*, physiopathology Ventricular Function, Right* Ventricular Pressure* |
| Grant Support | |
ID/Acronym/Agency:
|
R01-HL-92088/HL/NHLBI NIH HHS; T32-HL-07776/HL/NHLBI NIH HHS |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Losartan improves aortic endothelium-dependent relaxation via proline-rich tyrosine kinase 2/Src/Akt...
Next Document: Pressure-Volume Relation Analysis of mouse Ventricular Function.