Measurement of Local Myocardial Perfusion by Thermal Diffusion Microprobe during Coronary Artery Occlusion and Reperfusion in a Beating Canine Heart

Abstract

BACKGROUND: The measurement of perfusion is very important to understand the physiology of the tissue level. The QFlow(TM)400 perfusion measurement system is able to measure local tissue perfusion. The aim of this study was to validate thermal diffusion microprobe (TDM) in estimating myocardial blood flow during coronary artery occlusion and reperfusion in an animal beating heart model.0aMETHODS: A total of 5 mongrel dogs were entered into the study. A left thoracotomy was performed under general anesthesia. After the left anterior descending coronary artery (LAD) was exposed, a TDM was inserted in the myocardium at the exposed LAD distributed area. The local myocardial perfusion was measured before, during and after LAD occlusion. To find the usefulness of TDM in a beating heart, k values were checked during the study. The k value or tissue conductivity should not exceed 6.23 mW/cmoC in this system.0aRESULTS: All the k values were below 6.23 mW/cmdegreesC in this study. Baseline local myocardial perfusion was 52.0 /- 17.2 ml/min/100 g, respectively, but the values at 20 and 30 minutes of reperfusion were significantly lower compared to baseline value.0aCONCLUSIONS: We could use the QFlow(TM)400 perfusion measurement system to measure myocardial injury produced by ischemia and subsequent reperfusion in a beating heart. With this system, we found that the local myocardial perfusion was not recovered to the baseline level in early state of the coronary reperfusion.