Sponsor and site were unable to complete a final contract to support the study

Encouraged by the recent data published ,the investigators think that a waiting time of 10 minutes is feasible while preserving diagnostic accuracy and would like to assess the feasibility and diagnostic efficacy of W10 compared with W30 imaging in a pilot study. By combining W10 imaging with half-time acquisition, the time of the technetium-99m myocardial perfusion imaging procedure could be shortened by at least 50%, lasting only 40 minutes for W10 (10-minute waiting) imaging compared with 90 minutes for W30 imaging (30-minute waiting).

The investigators hypothesize that (1) W10 MPI is clinically feasible and tolerable by the patients, that (2) W10 MPI provides high image quality and that (3) W10 MPI provides diagnostic accuracy comparable to W30 MPI.

Inclusion Criteria:

• Men and women ≥18 and ≤ 89 years of age of any race /ethnicity
• Patient has undergone or is being scheduled for a clinically indicated CardiacCath with or without angioplasty
• Patient may have suffered myocardial infarction more than 3 days before T99m-MPI
• Patient may have undergone percutaneous transluminal coronary angioplasty (PTCA) or coronary stent placement more than 3 days prior to T99m-Myocardial Perfusion Imaging (MPI)
• Interval between T99m-MPI and CardiacCath is within 30 days
• Females cannot be pregnant or lactating
• Women of no child-bearing potential (post-menopausal defined as amenorrhea ≥ 12 consecutive months, or because they have undergone successful surgical sterilization and deny current history of pregnancy and nursing). These subjects do not require serum pregnancy test on the day of the study
• Women of childbearing potential will require a negative serum pregnancy test, performed on the day of the study
• Provide signed Informed Consent prior to undergoing the study procedures

Exclusion Criteria:

• Patients less than 18 and ≥89 years of age
• Patient has been involved in any other investigative, radioactive research procedure within 7 days and during the study participation period
• History of 2nd or 3rd degree Atrio-ventricular-block, or sinus node dysfunction unless the patients have a functioning artificial pacemaker
• Current ventricular tachycardia, atrial fibrillation, atrial tachycardia, or atrial flutter
• Current unstable angina or cardiovascular instability
• Current history of exacerbated Chronic Obstructive Pulmonary Disease (COPD) or asthma
• Known hypersensitivity or contraindication to regadenoson or aminophylline
• Use of caffeinated substance, dipyridamole-containing medication, aminophylline, or xanthines containing medication (e.g. theophylline) within the 12 hours prior to Lexiscan administration