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This Article Full Text Full Text (PDF) All Versions of this Article: 107/3/921    most recent 00275.2009v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Schmitt, B. Articles by Kuehne, T. PubMed PubMed Citation Articles by Schmitt, B. Articles by Kuehne, T.

Three-dimensional alignment of the aggregated myocytes in the normal and hypertrophic murine heart

¹Unit of Cardiovascular Imaging—Department for Congenital Heart Disease and Pediatric Cardiology, German Heart Institute Berlin, ²Institute for Informatics, University of Münster, Germany; ³Institute for Biomedical Engineering, Swiss Federal Institute of Technology (ETH) Zurich and University Zurich, Switzerland; ⁴ Phillips Medical Systems, Hamburg, ⁵Institute of Cardiology, Charité, Campus Benjamin Franklin, Berlin, ⁶Department of Thoracic and Cardiovascular Surgery, University Hospital Münster, Germany; and ⁷Cardiac Unit, Institute of Child Health, University College, London, United Kingdom

Submitted 13 March 2009 ; accepted in final form 16 July 2009

Several observations suggest that the transmission of myocardial forces is influenced in part by the spatial arrangement of the myocytes aggregated together within ventricular mass. Our aim was to assess, using diffusion tensor magnetic resonance imaging (DT-MRI), any differences in the three-dimensional arrangement of these myocytes in the normal heart compared with the hypertrophic murine myocardium. We induced ventricular hypertrophy in seven mice by infusion of angiotensin II through a subcutaneous pump, with seven other mice serving as controls. DT-MRI of explanted hearts was performed at 3.0 Tesla. We used the primary eigenvector in each voxel to determine the three-dimensional orientation of aggregated myocytes in respect to their helical angles and their transmural courses (intruding angles). Compared with controls, the hypertrophic hearts showed significant increases in myocardial mass and the outer radius of the left ventricular chamber (P < 0.05). In both groups, a significant change was noted from positive intruding angles at the base to negative angles at the ventricular apex (P < 0.01). Compared with controls, the hypertrophied hearts had significantly larger intruding angles of the aggregated myocytes, notably in the apical and basal slices (P < 0.001). In both groups, the helical angles were greatest in midventricular sections, albeit with significantly smaller angles in the mice with hypertrophied myocardium (P < 0.01). The use of DT-MRI revealed significant differences in helix and intruding angles of the myocytes in the mice with hypertrophied myocardium.

hypertrophy; orientation; magnetic resonance imaging; diffusion tensor imaging