• ELIGIBILITY CRITERIA:

No one will be excluded from this study based on race, gender, or ethnicity.

A. General Inclusion Criteria:

• Age greater than or equal to 18 (children are excluded because coronary disease is rare in this population).
• Capable of giving informed consent.

B. General Exclusion Criteria (for all arms):

• Pregnant women (uncertain patients will have urine or blood testing).
• Decompensated heart failure (unable to lie flat in bed).

Test Specific Exclusion Criteria:

A. CT Exclusion Criteria (excludes contrast enhanced CT scan only):

• Allergy to iodinated contrast agent excludes contrast enhanced CT research studies.
• Multiple myeloma.
• Patients with severe kidney disease (eGFR less than 30 mL/min/1.73 m(2).

B. Beta Antagonist Exclusions (excluded the use of beta blocker only):

• Asthma or severe chronic lung disease/emphysema with regular use of inhaler.
• Decompensated heart failure.

C. MRI Exclusion Criteria (excludes MRI scan only):

• Cardiac pacemaker or implantable defibrillator.
• Cerebral aneurysm clip.
• Neural stimulator (e.g. TENS-Unit).
• Any type of ear implant.
• Metal in eye (e.g. from machining).
• Any implanted device (e.g. insulin pump, drug infusion device).

D. Exclusions from MRI contrast agents:

• Lacting women unless they are willing to discard breast milk for 24 hours.
• Severe kidney disease (mL/min/1.73 m(2).

E. Vasodilator Exclusions (excludes some vasodilator stress testing):

• Asthma or chronic obstructive pulmonary disease (emphysema) actively treated with bronchodilators or leukotriene receptor antagonists (albuterol, seravent, atrovent, montelukast singulair (® (Registered Trademark)), zafirlukast Accolate® (Registered Trademark). These conditions only exclude adenosine and dipyridamole.
• Second degree (Type II) and third degree atrioventricular heart block.

F. Exclusions from Dobutamine stress MRI only:

• Severe problems with heart rhythms.
• Severe high blood pressure.

G. Exclusion criteria for atropine (given during dobutamine stress echocardiography when target heart rate not achievable with dobutamine alone).

• Narrow angle glaucoma.
• Known or suspected severe bladder outlet obstruction due to prostatic hypertrophy.