Mr Alexander James Wilson
BSc PGDipSci MOR
Alexander has a Bachelor of Science in Biomedical Science, a Postgraduate Diploma in Science with Merit in Medical Science, and a Master of Operations Research with First Class Honours. These are all from the University of Auckland.
Research | Current
Biomechanics of Diastolic Heart Failure
Heart failure (HF) is a condition in which cardiac output of blood does not meet the requirements of the body. HF is the result of maladaptive cardiac remodelling which alters myocardial structure and ventricular function. Conventionally HF has been identified as impaired ventricular contraction indicating systolic dysfunction. Clinical studies have revealed that systole is impaired in only half of HF cases, the other half exhibiting diastolic dysfunction. Current HF treatments were developed targeting patients with systolic dysfunction and these treatments are ineffective in altering the progression of HF with diastolic dysfunction. Structural changes, both at the global scale of chamber geometry, and at the microscopic scale, are different in the two forms of HF. In order to design mechanisms-targeted treatment, new insights must be gained regarding the multi-scale relationships between myocardial structure and ventricular function.
This study investigates the structure-function relationship using the spontaneously hypertensive rat (SHR) as a model of HF. The SHR exhibits progressive maladaptive cardiac remodelling which is similar to human HF. A spectrum of structural and functional data was obtained by taking measurements from groups with different degrees of cardiac remodelling, at a range of ages. Groups of untreated SHRs were compared with both angiotensin-converting enzyme-inhibitor (ACEi) treated SHRs and Wistar-Kyoto (WKY) controls. ACEi treatment has been shown to decrease interstitial collagen and alter ventricular function. Including this treatment group provided an additional degree of cardiac remodelling. Each animal underwent cardiac magnetic resonance imaging (MRI), allowing assessment of systolic and diastolic function. MRI tissue tagging studies provided regional deformation data including radial, circumferential and longitudinal strains as well as ventricular torsion. Cine MRIs formed the basis of individualised finite element models of the left ventricle (LV) and the addition of tagged data allowed for a full kinematic analysis of ventricular function. LV pressure was measured during MRI scans and passive pressure-volume curves were subsequently obtained in the excised, Langendorff-perfused heart. A collagen-specific stain was applied and the microstructure of the myocardium was investigated using extended-volume confocal microscopy of LV tissue blocks. The ACEi treated SHRs were observed to have a decreased LV mass and an elevated EF relative to untreated SHRs. Extended-volume confocal microscopy revealed altered microstructural architecture suggesting an underlying structural basis to the functional changes. Analysis of the structural and functional data in a modelling environment provided new insight into the multi-scale relationship between cardiac remodelling and ventricular diastolic dysfunction.
Selected publications and creative works (Research Outputs)
- Wang, Y., Huang, S.-M., Wilson, A., Sands, G., Young, A., Le Grice, I. J., & Nash, M. P. (2013). Structural Imaging and Modelling The Mechanics of Heart Failure. In J. A. Weiss, G. A. Ateshian (Eds.) Proceedings of the 11th International Symposium on Computer Methods in Biomechanics and Biomedical Engineering Salt Lake City. Related URL.
Other University of Auckland co-authors: Ian LeGrice, Alistair Young, Martyn Nash, Vicky Wang, Gregory Sands
- Wang, Y., Huang, S.-M., Wilson, A., Sands, G. B., Young, A. A., LeGrice, I. J., & Nash, M. P. (2013). Structural Imaging and Modelling the Mechanics of Heart Failure. Paper presented at Computer Methods in Biomechanics and Biomedical Engineering, Salt Lake City, UT, USA. 3 April - 6 April 2013. 11th International Symposium of the CMBBE.
Other University of Auckland co-authors: Vicky Wang, Ian LeGrice, Alistair Young, Martyn Nash, Gregory Sands
- Wilson, A. J. (2011). Optimal Electricity Distribution Tariff Design The University of Auckland. ResearchSpace@Auckland. Related URL.