A Trial Evaluating the Clinical Applicability, Correlation, and Modeling of Cardiac CT Using 64 Detector Row VCT

Inclusion Criteria: * Patients scheduled for elective diagnostic catheterization OR * Elective diagnostic catheterization has been performed within the past 2 weeks but no less than 24 hours prior to the coronary CTA procedure with no intervention performed or change of the patient clinical status. * Age ≥18 years but ≤75 years. Exclusion Criteria: * Prior coronary stent implantation * Prior coronary artery bypass grafting or other heart surgery * Prior pacemaker or internal defibrillator lead implantation * Prior artificial heart valve * Biochemical renal insufficiency (CrSerum \> 1.6) or on dialysis * Resting HR \> 100 at the time of enrollment * Contraindication to β-blockade or calcium channel blocker * NYHA-IV * High-grade atrioventricular (AV) block * Systolic blood pressure \<90 mm Hg * Severe asthma or active bronchospasm and/or chronic obstructive pulmonary disease * Atrial fibrillation * Inability to provide informed consent * Evidence of ongoing or active clinical instability * Acute chest pain (sudden onset) * Acute myocardial infarction * Cardiac shock * Acute pulmonary edema