Details

Autor(en) / Beteiligte

• Ashikaga, Hiroshi
• Omens, Jeffrey H
• Covell, James W

Titel

Time-dependent remodeling of transmural architecture underlying abnormal ventricular geometry in chronic volume overload heart failure

Ist Teil von

• American journal of physiology. Heart and circulatory physiology, 2004-11, Vol.287 (5), p.H1994-H2002

Ort / Verlag

United States

Erscheinungsjahr

2004

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• Departments of Medicine and Bioengineering, University of California, San Diego, La Jolla, California 92093 Submitted 13 April 2004 ; accepted in final form 30 June 2004 To test the hypothesis that the abnormal ventricular geometry in failing hearts may be accounted for by regionally selective remodeling of myocardial laminae or sheets, we investigated remodeling of the transmural architecture in chronic volume overload induced by an aortocaval shunt. We determined three-dimensional finite deformation at apical and basal sites in left ventricular anterior wall of six dogs with the use of biplane cineradiography of implanted markers. Myocardial strains at end diastole were measured at a failing state referred to control to describe remodeling of myofibers and sheet structures over time. After 9 ± 2 wk (means ± SE) of volume overload, the myocardial volume within the marker sets increased by >20%. At 2 wk, the basal site had myofiber elongation (0.099 ± 0.030; P < 0.05), whereas the apical site did not [ P = not significant (NS)]. Sheet shear at the basal site increased progressively toward the final study (0.040 ± 0.003 at 2 wk and 0.054 ± 0.021 at final; both P < 0.05), which contributed to a significant increase in wall thickness at the final study (0.181 ± 0.047; P < 0.05), whereas the apical site did not ( P = NS). We conclude that the remodeling of the transmural architecture is regionally heterogeneous in chronic volume overload. The early differences in fiber elongation seem most likely due to a regional gradient in diastolic wall stress, whereas the late differences in wall thickness are most likely related to regional differences in the laminar architecture of the wall. These results suggest that the temporal progression of ventricular remodeling may be anatomically designed at the level of regional laminar architecture. heart failure; fiber; myocardial lamina; finite deformation Address for reprint requests and other correspondence: J. W. Covell, Dept. of Medicine, Univ. of California, San Diego, 9500 Gilman Dr., 0613J, La Jolla, CA 92093 (E-mail: jcovell{at}ucsd.edu )