Are you experiencing symptoms that may indicate heart disease? If so your primary care physician will typically refer you to a cardiologist. There are many tests that cardiologists can employ to diagnose heart-related problems. A nuclear medicine test is one of the most commonly performed non-invasive diagnostic heart tests. It is typically done to diagnose coronary artery disease, get an accurate picture of the size and shape of your heart, and guide treatment of heart disorders. It can easily be done in your physician’s office with minimal risk.
For this diagnostic test, a small dose of a radioactive nuclear isotope is injected into your bloodstream and absorbed by the heart muscles. The heart muscle with normal blood flow receives larger amounts of the isotope and appears brighter than the muscle with inadequate blood flow. These captured colored images provide useful information to your physician to evaluate your heart’s condition.
Usually, this is done with one of two procedures:
This type of nuclear medicine imaging test is done in conjunction with a treadmill stress test and measures blood flow to your heart at rest and blood flow to your heart with exertion. Prior to the start of the test, cardiolite, a nuclear radioactive isotope, is injected into your bloodstream. A first set of images will be taken of your heart at rest, before exercise begins. These readings can be used to ensure that you are ready for the test and are compared to the images of the heart under stress (exercise). After the first set of images are completed, you will move to the treadmill. Typically the speed and incline of the treadmill are increased in 3-minute intervals to increase exertion. You will continue walking until you reach a maximum predicted heart rate (typically 5 to 15 minutes). Your heart rate, EKG and blood pressure are measured during the entire course of exercise. After exercise you will receive more radioactive dye and lie on the imaging table where a second set of images will be taken.
A pharmacological approach to nuclear imaging is used for those who may not do well with the treadmill stress test. This procedure involves the use of Lexiscan, a prescription medication that increases blood flow to the heart by dilating your coronary arteries. This medication is injected into your bloodstream through an IV. A nuclear radioactive isotope is also injected through the IV line, which gives your doctor a detailed view of your heart, making it easy to check if there are any blockages that are preventing blood flow to your heart.
Typically you are asked to not eat or drink anything including water prior to the test. Ask your doctor if you should avoid caffeine and certain medications the day prior to the test as well. If you use an inhaler, they will ask that you bring it to the test. Typically the test can take 2-4 hours. Please wear comfortable clothing and walking shoes.
If you have any risk factors for heart disease (e.g. hypertension, high blood cholesterol, diabetes, smoking, family history of heart disease) and you’re experiencing symptoms of heart problems like chest pain and shortness of breath, scheduling a visit to discuss symptoms is highly recommended.
Other posts you might be interested in:
Published June 14, 2019