A Novel Experimental Rat Model for the In Vivo Assessment of Myocardial Ischemia Based on Single Photon Emission Computed Tomography.

Abstract

Myocardial infarction, an acute medical situation with a high mortality rate worldwide, has been extensively studied in modern cardiovascular research, using different experimental models. However, a deep understanding of myocardial activity loss has not been fully investigated. We have developed a novel experimental rat model for noninvasive assessment of myocardial ischemia based on single photon emission computed tomography (SPECT/CT), in order to further understand and evaluate myocardial activity before and after surgical induction of myocardial ischemia. Thirty adult female Wistar rats underwent open thoracotomy with (n=20) or without (n=10) surgical ligation of the left anterior descending coronary artery (LAD). The myocardial ischemia was confirmed with ECG and myocardial viability was evaluated via SPECT/CT at 7 days before as well as at 7 and 14 days post-surgery, after which animals were sacrificed and myocardial ischemic injury was further assessed histologically. All animals were evaluated with anatomical and functional criteria based on the SPECT/CT imaging results. A successful surgical technique causing ischemia and loss of myocardial function in all animals undergoing a LAD ligation was established. Furthermore, evaluation of the viable myocardium with SPECT/CT confirmed the reduction of functional myocardial cells of the left ventricle post-infarction, which was also documented histologically. Using our technique, the validity of this animal model to induce and evaluate myocardial ischemia was demonstrated. Our choice to apply SPECT-CT qualitative and quantitative evaluation of myocardial function leads to a new approach in experimentation with an anticipated significant impact in the ongoing cardiovascular laboratory research.