Adenosine Cardiac Magnetic Resonance Imaging

The adenosine cardiac magnetic resonance imaging (MRI) procedure takes pictures created by a magnetic field, radio waves and a computer to evaluate the flow of blood to the heart muscle. This procedure looks at areas of a patient's heart that may not be receiving adequate blood supply.

Adenosine Cardiac MRIs may be used to diagnose several heart disorders including coronary large artery blockage and small vessel disease. It also may be used to confirm that a patient's heart medication is working to normalize blood flow to the heart muscle and reduce the insufficient blood flow called "ischemia." Some physicians order this test as a baseline before heart surgery or prior to coronary reactivity testing.

Who May Not Be a Candidate for Adenosine Cardiac MRI Testing

Not all heart or potential heart patients will be candidates for this procedure. Patients with the following conditions may not be allowed to have the test:

  • Those with magnetic material in their body, a pacemaker, an implantable cardioveter-defibrillator (ICD) or a brain aneurysm clip.
  • Those with unstable angina, a recent heart attack or heart failure, and severely high or low blood pressure.
  • The MRI machine is a tube with a three foot wide opening in the center which may be difficult for patients with severe claustrophobia or a body weight of more than 300 pounds.
  • Those with asthma or severe obstructive pulmonary disease who cannot take adenosine.
  • Those with kidney failure.
Preparing for the Adenosine Cardiac MRI Test

Physicians will ask for a complete list of the patient's medications, including vitamin and mineral supplements, and a list of the patient's medication allergies. With this information, the physician can issue instructions on what medications a patient should stop using and when.

Patients will be instructed not to eat or drink anything within eight hours of the test and how to take their allowed medications. Any caffeinated or decaffeinated products must be avoided entirely at least 12 hours before testing.

During the Adenosine Cardiac MRI Test

After an electrocardiogram (EKG) is taken, patients will be set up with two intravenous (IV) lines, one in each arm, a blood pressure cuff and a heart monitor. One IV line will release a medication called "adenosine" which affects the heart the way exercise would by increasing heart rate and blood pressure. Because adenosine simulates the effects of exercise on the heart, the procedure will be stopped if the patient experiences any chest pain or shortness of breath or heartbeat changes. Once the adenosine is stopped, the patient should quickly return to normal.

Once the heart is "stressed," the other IV line releases a contrast agent, gadolinium-DTPA, so a picture of the heart can be taken.

Patients should allow adequate time for the procedure. Testing time varies with each patient and is commonly about 90 minutes. Patients will be able to communicate with the radiologist throughout the procedure. MRI procedures are noisy with a lot of thumping and beeping. Ear plugs will be provided and you may bring a CD to listen to although you may only be able to hear it intermittently. MP3 players with earphones are not allowed during the MRI.

After the Adenosine Cardiac MRI Test

Patients will be given follow-up and contact information. Unless instructed otherwise, patients should be able to return to normal activity quickly and resume their medications. Follow-up visits and/or phone calls with the primary care physician for test results and a treatment plan will be necessary. Because the results of the test are complex computerized images, a final report may take up to 24 to 48 hours to be completed.