A large number of cardiac catheterizations are performed each year, primarily to diagnose heart disease. However, a cardiac catheterization is an invasive procedure which is associated with serious complications such as heart infarction, stroke, and death. Therefore, there is a need for non-invasive procedures to diagnose coronary heart disease. The purpose of this study is, therefore, to assess the diagnostic accuracy of non-invasive cardiac imaging modalities for the detection of heart disease in patients presenting for the first time to the cardiologist with chest pain.