Thermal Response of Heart Tissue

The Texas Heart Institute, in cooperation with the Heat Transfer and Phase Change Laboratory of the Department of Mechanical Engineering, is studying the thermal response of heart tissue to the acute cessation of coronary blood flow.

The research seeks to establish a link between ischemia and the temperature of the heart that may lead to a new early detection mechanism for heart disease. In experiments performed on swine, blood flow in a single coronary artery is blocked.

The temperature of a part of the heart muscle fed by that artery is monitored along with the pumping work produced at that location. Microthermocouple probes constructed by a UH graduate student and implanted by surgeons at the Texas Heart Institute are used to measure tissue temperature. An example of these probes is shown in the figure (upper right).
An ultrasound probe developed at the Baylor College of Medicine is used to measure the local work rate. The graph shows an example response to a five-minute occlusion. The tissue temperature rises slightly as the work produced per heat beat drops.

This response indicates that the pumping efficiency of the muscle is dropping rapidly at the onset of the occlusion. When blood flow is restored, the temperature falls and the magnitude of the pump work is restored.

Short Biography
Professor Keith Hollingsworth received his B.S. and M.S. from North Carolina State University, and Ph.D. from Stanford University. He is the recipient of the highest teaching awards at both the College and University levels, and the El Paso Energy Corp. Faculty Achievement Award.