What is a cardiac MRI?
Using powerful magnetic fields, the MRI machine can obtain very detailed pictures of your heart and blood vessels. You are not exposed to any radiation, but because of the powerful magnets inside the MRI machine, you will be asked about any prosthetic material you may have in your body. Heart valves, cardiac stents, and prosthetic joints are generally safe, but if you have a pacemaker or defibrillator you should not have an MRI.
Why is it ordered?
Cardiac MRI can be very helpful when making the decision to send patients for open heart surgery. In patients with coronary artery disease the MRI can distinguish between areas that have suffered a small heart attack, and those areas of heart muscle that are still alive, but are starved of blood supply and oxygen due to narrowing of the coronary arteries. It is also very helpful when patients have severe mitral regurgitation or aortic regurgitation because you can determine the exact size and volumes of the heart chambers, and how much blood is leaking with each heartbeat. MRI can also help with the diagnosis of diseases of the aorta, problems with the fibrous sack surrounding the heart called the pericardium, and in evaluating patients with congenital heart disease.
What can I expect the day of my test?
- If you. are claustrophobic ask your doctor about a sedative medication.
- If you need to take a sedative, someone will have to drive you to and from your test.
- Adhesive patches will be placed on your skin to monitor your electrocardiogram.
- You will lie down in the MRI machine for 20-45 minutes while the pictures of you heart are obtained
- You may be asked to hold you breath during the test.
- The machine makes noises during your test; you are provided with headphones to listen to music and drown out the noise.
- An IV may be placed to give you a contrast agent called gadolinium.