Thermal imaging of myocardial perfusion in an acute myocardial infarctus model in rats

Objective: The aim of this study was to develop a non-invasive measurement method using thermal imaging for the intraoperative evaluation of myocardial perfusion in cardiovascular surgery. Materials and Methods: The evaluation of perfusion changes in the heart in acute myocardial infarction (MI) models was conducted using 40 Wistar albino rats. MI models were induced by isoproterenol administration as a positive control. The left anterior descending coronary artery was occluded for 15 and 30 minutes to induce ischemia, followed by reperfusion. Images were recorded every five minutes, and energy metabolism was correlated with myocardial temperature changes. Results: The energy metabolism, temperature changes in the heart, and histopathological evaluations of the positive control group treated with 40 mg/kg isoproterenol were similar to the group subjected to 15 minutes of ischemia and 15 minutes of reperfusion. All temperature changes in the heart were detected with a sensitivity of 0,010°C, and the differences between groups were statistically significant (p<0,01). Conclusion: In this study, it was concluded that thermal imaging, by recording temperature changes in the heart during the process of ischemia and reperfusion, can accurately visualize myocardial perfusion. In order for the thermal camera to be used effectively during surgery, thermal contrast of the area to be evaluated must be provided. However, considering the emergency situations that require rapid intervention during the incident, special and compact systems are needed that will provide information in a very short time and provide the opportunity to intervene in a very short time. In order for these systems to be ergonomic, software specific to the surgical branch should be developed and an information library should be created by increasing the number of case examples.