1. Development of an optical mapping facility for large hearts using a Dalsa CCD camera.

Photo of the Dalsa CCD camera used for imaging changes in fluorescence emitted from hearts perfused with voltage sensitive dyes.

2. Development of an optical mapping facility for small hearts using a Hamamatsu Photo Diode Array. For more information click here.

3. Electrical imaging of normal and genetically altered small hearts. For more information click here.

Research Interests

Diabetes affects over 130 million people worldwide. Associated with this disease is a 2 to 6-fold increased risk for cardiovascular disease and a 67% increased risk of cardiac death. As death rates due to cardiovascular disease have decreased in this country by approximately 30% for non-diabetics over the last 30 years, death rates for diabetic men have only decreased 13% and diabetic women have seen an increase of 27%. These numbers reflect the urgent need to understand why the setting of diabetes offers more lethal cardiac outcomes than for other patients. The primary focus of my laboratory is to investigate this lethal link between diabetes and cardiovascular disease.
Working with genetically modified mouse models associated with diabetes, we are applying voltage-sensitive optical imaging, conventional electrical imaging, tissue resistivity measures and measures of calcium and potassium ions to phenotype electrophysiologic changes associated with some specific aspects of diabetes, namely insulin resistance and the down regulation of glucose transport.
One mouse model that we are currently studying was developed and metabolically characterized in the laboratory of E. Dale Abel, MD, Ph.D. at the Eccles Institute for Human Genetics at the University of Utah. It is a cardiomyocyte insulin receptor knock-out (CIRKO) mouse that eliminates insulin signaling in the heart. Previous studies from our laboratory have shown these hearts to exhibit impaired electrical propagation, particularly during ischemia, due to reduced repolarizing currents.
We are also currently studying the effects of glucose levels and insulin signaling on the electrical activity during hypoxic and ischemic conditions in Langendorff perfused isolated mouse hearts. Decreased levels of ATP available to diabetics during ischemia increase the occurrence of ischemic and reperfusion injury and we are characterizing the direct relationship between electrical activity and glucose and insulin availability.