This book assesses the correlation between cardiac ischemic score and coronary collaterals and to provide an alternative treatment option, in patients with ischemic heart disease, who are not suitable for conventional revascularization therapies. Coronary collateral circulation maintains myocardial perfusion in coronary atherosclerotic disease. The indicators of cardiac ischemia, like (Angina pectoris on exertion, during emotion, previous myocardial infarction, prior coronary intervention), are associated with presence of coronary collateral circulation in different studies abroad. The study correlating the coronary collaterals and the indicators of cardiac ischemia was not performed in Bangladeshi population and hence this study was carried out here. This prospective observational cross sectional study was carried out in department of Cardiology, BSMMU from January 2007 to December 2008. A total of 128 patients with angina pectoris and or MI and or previous coronary intervention undergoing CAG and PCI were included in the study.