5.0 Measurements Baseline absolute coronary flow and CFR will be obtained for each major coronary artery territory [left anterior descending (LAD), left circumflex (LCx), right coronary (RCA)] using FDA-approved software. Vessels will be divided into two groups: 1) those in which the baseline perfusion defect matched the revascularized territory and 2) those in which there was no baseline defect in the revascularized territory. The change in pre-vascularization and post-vascularization myocardial blood flow will be compared between the two groups. Chart review and participant interviews will include patient demographics, complete medical history, physical examination, laboratory data, 12-lead electrocardiogram (ECG), Canadian Cardiovascular Society grading of angina pectoris, and procedure reports for LHC and revascularization procedures.