ISSN Online: 2377-424X
ISBN Print: 0-85295-345-3
International Heat Transfer Conference 10
CORONARY BLOOD FLOW AND CARDIAC SURFACE TEMPERATURE BY THERMAL IMAGING
摘要
The temperature of the coronary vessels and myocardium in open chest operations reflects the rate of the coronary blood flow and myocardial perfusion. The temperature is mostly determined by convection, perfusion, conduction through the myocardium, local heat production by metabolism and, negligibly, radiation and evaporation. The temperature of the epicardial surface is obviously sensitive to local blood flow reduction (ischemia). Injection of a bolus of cold saline into the aorta which feeds the coronary vessels generates a transient temperature response which depends upon the myocardial blood flow. The network of epicardial arteries appear on the thermographic image and decays rapidly. The thermal response of the myocardium is apparent later. The relationships between myocardial thermal washout response in an arterial and myocardial segment, and the local coronary perfusion, are studied. It is shown that the temperature washout curve of the myocardium is a function of coronary flow. A theoretical model of heat transfer in the myocardium is used to analyze the experimental observations, and study the application of thermography as a tool to assess myocardial perfusion simultaneously with the coronary anatomy during open chest conditions.