The Value of Tc-MIBI Washout Rate in Detection of Myocardial Ischemia

Ischemic Heart Disease is defined as myocardial impairment due to an imbalance between coronary blood flow and myocardial requirements caused by changes in the coronary circulation. Coronary artery disease is thought to arise from normal repair processes in response to chronic injuries to the arterial endothelium. The stresses are enhanced by hypertension,hyper-cholesterolemia,end-products of diabetes and tobacco smoke. The diagnosis of coronary Heart Disease(CAD) involves clinical evaluation identifying significant risk factors and specific cardiac investigations to confirm the diagnosis to evaluate the efficacy of treatment. Myocardial Perfusion Scan (MPS) using 99mTc-MIBI perfusion imaging with 90% of it localized within mitochondria. It is of high prognostic value as normal MPS suggests the absence of CAD and associated with a low likelihood of MI. While, an abnormal scan indicates the presence of significant CAD. The retention of MIBI in myocyte is highly related to normal mitochondrial function.The situations that MIBI reverse redistribution i.e. accelerated MIBI washout, is proved to be of clinical significance include ischemic heart disease.