My research interests include magnetic resonance imaging for assessment of LV function in ischemic heart disease R01 HL62291.

Prediction of Myocardial Recoverability by 3D MRI

Atherosclerotic disease of the coronary arteries is the most common reason for cardiac surgical intervention. Improvements in the preoperative quantification and three-dimensional (3D) visualization of regional viability and ischemia will improve our ability to predict myocardial recoverability after revascularization and, therefore, to tailor surgical intervention to individual patient risk and benefit. In this regard, the use of advanced mathematical modeling methodologies to accurately characterize biventricular stress/strain relationships and display three-dimensional (3D) biventricular stress and strain distribution has ushered in a new era of clinical cardiac analysis.

Magnetic resonance imaging (MRI)-based, 3D left ventricular geometrical data-sets obtained using radiofrequency tissue tagging techniques can be combined with simultaneously acquired systolic loading conditions and advanced finite element modeling techniques to characterize regional systolic strain and stress in 3D.

We are currently testing the clinical applicability and utility of these newly developed systolic indices, which we believe most accurately reflect systolic function at the cellular level, by characterizing response to Dobutamine in normal and impaired left ventricular wall regions before and after surgical revascularization.

Genomic approaches to the study of ascending aortic aneurysms associated with bicuspid aortic valve (funded by an SS-50 grant, Mayo Clinic).

Bicuspid aortic valve (BAV) disease affects 1-2% of the population. Ascending aortic aneurysms (AscAA) may be associated with BAV, although the frequency of this phenotype is unclear. Intrinsic abnormality of the aorta has been proposed as a mechanism but remains unproven. The natural history of this aorta is undefined, as is its behavior following surgical intervention on the aortic valve. Accordingly, the answers to clinical questions such as the appropriate time of surgical intervention on the AscAA, the extent of surgical resection, and the management of mildly dilated aorta at the time of aortic valve replacement remain uncertain. We hypothesize that AscAA associated with BAV are due to inherent abnormality of the aortic wall. We further hypothesize that this abnormality is genetically determined.

The specific aims of our work are:

1) To establish a resource for translational research taking advantage of the robust clinical practice at the Mayo Clinic by creating a tissue bank of surgical specimens of AscAA, an associated DNA bank, and a carefully maintained record of phenotypic details, physiologic parameters, and clinical histories.

2) To carry out analysis of materials described in #1 using DNA microarray technology.