Multi-scale analysis of cardiac myoarchitecture

The distribution and generation of force within the myocardium during normal contractility is dictated by the tissue's underlying 3D myoarchitecture. The presence of disordered myoarchitecture may in turn constitute the pathological basis of impaired cardiac mechanics in numerous clinical conditions, such as the remodeling heart following myocardial infarction and cardiomyopathies. To investigate the multi-scale nature of architectural disarray in the setting of myocardial disease, a dual imaging approach consisting of diffusion spectrum magnetic resonance imaging (DSI) and high-speed multislice two-photon microscopy (TPM) was used. DSI is a technique that derives fiber orientation from directionality of proton diffusion, whereas TPM derives cellular alignment from an autocorrelation of 3D resolved images of cells and subcellular structure. Mesoscale tract representations of myofiber orientation are generated from similarly aligned diffusion or autocorrelation vectors. These methods were applied to study induced myocardial infarction in the rat and hypertrophic cardiomyopathy associated with deletion of the gene for myosin binding protein C (cMyBP-C) in the mouse. Normal cardiac muscle fiber alignment within the ventricular wall was characterized by a series of helical tracts transitioning from a lefthanded orientation in the subepicardium to circumferential in the mid-myocardium to righthanded in the subendocardium. Infarcted hearts displayed a fiber void in the infarct zone and an extension of both subepicardial and subendocardial fibers beyond the border zone. It's hypothesized that the growth of fibers contributes to the remodeling process and provides tensile strength to the myocardium during contraction.

Department dc:contributor.department

Massachusetts Institute of Technology. Biological Engineering Division.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2008

Author dc:creator

• Wang, Teresa T

Advisor dc:contributor.advisor

• Peter So and Richard Gilbert.

• Biological Engineering Division.

Statement dc:rights

• MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/45210

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/45210