Comparison of Dobutamine and Regadenoson Stress Cardiac Magnetic Resonance (MR)

Comparison of Dobutamine and Regadenoson Stress CMR

The goal of this research is to determine the utility of Regadenoson (Lexiscan)for use as an imaging agent with cardiac MR. If found useful, it will help us establish a protocol for regadenoson stress MR perfusion (Regadenoson stress test with cardiac MR).The investigators will compare regadenoson with dobutamine so each participant will undergo two studies. A cardiac MR stress test with regadenoson and with dobutamine. The investigators participants will include patients with history of COPD and Asthma, so it will also help us determine feasibility of Regadenoson in these patient's subgroups.

Inclusion Criteria:

• Men and women aged 40 to 85 years with OBSTRUCTIVE AIRWAY DISEASES (ASTHMA AND COPD) and a forced expiratory volume (FEV1) > 0.5.
• Patients should have a clinical indication to undergo cardiac stress test with dobutamine.

Exclusion Criteria:

• Those with pacemakers, defibrillators, functioning neural stimulator devices or other implanted electronic devices.
• Ferromagnetic cerebral aneurism clips or other intraorbital and intracranial metal.
• An allergy to Gadolinium or other severe drug allergies.
• Acute myocardial infarction within 3 months.
• Moderate or severe aortic stenosis or other significant valvular disease;
• Claustrophobia.
• High grade (2o or 3o) AV Block.
• Closed angle glaucoma.
• Participants unable to provide informed consent.
• Renal dialysis (subjects with moderate-to-severe renal impairment defined as eGFR < 60 mL/min.
• A contraindication to receipt of dobutamine.
• Participants with known coronary artery disease will be included with the exception that patients with left main or narrowings >50% in the distributions of the left anterior descending, circumflex, and right coronary artery will be excluded.