A Cardiolite® nuclear stress test is a specialized diagnostic procedure that shows how well your heart functions when forced to pump more blood than usual.
Experienced cardiologist Laura Fernandes, MD, FACC, at Woodlands Heart and Vascular Institute, uses the test to detect blockages in the blood flowing through your heart and to recommend personalized treatment to protect your heart health.
A Cardiolite nuclear stress test involves an exercise or pharmacologic stress test:
An exercise stress test reveals how well your heart functions when forced to work harder. This type of test is crucial because it finds heart problems that only occur when the heart is under stress.
During the test, you walk on a treadmill that increases in speed (and possibly incline) at regular intervals. We check your blood pressure throughout the stress test.
You’re also connected to an electrocardiogram (EKG) machine that continuously shows your heartbeat. That lets us monitor changes in your heart function as the exercise intensity increases.
Not everyone can exercise, either because they have a severe heart condition or a physical problem that limits their activity. In that case, we can inject a medication that mimics the effects of exercise by increasing your heart rate.
You may only need an exercise test with EKG and blood pressure readings. But we may need to combine an exercise stress test with diagnostic imaging that shows the heart’s structures, as well as muscle and blood movement.
There are two primary types of imaging used: stress echocardiogram and Cardiolite nuclear stress test.
A stress echocardiogram combines ultrasound with an exercise stress test. We take ultrasound images before and after your stress test. By comparing the images, we can identify changes in the heart’s blood flow.
This test also takes images before and after an exercise or pharmacologic stress test. However, it uses radioactive tracers and advanced imaging to reveal additional details about the blood flow through your heart.
Cardiolite is a safe radioactive tracer (radiotracer). We insert an intravenous line and inject it into your bloodstream.
As the radiotracer flows through your heart, the heart's muscles pick it up in direct proportion to the amount of blood reaching the tissues. Areas of the heart with a healthy blood supply pick up more tracer than areas where the blood flow is blocked.
We inject Cardiolite before your stress test, and repeat it after you finish exercising. After injecting the radiotracer, you lie on a table, and we perform a type of imaging called single photon emission computed tomography (SPECT).
SPECT detects the gamma radiation emitted as the radiotracer breaks down. A specialized computer interprets the images, providing distinctive pictures of blood flow through your heart.
The SPECT images taken before and after exercise show small details not detected by other techniques, such as ultrasound, and which only occur when the heart undergoes stress.
As a result, we find specific areas with reduced blood flow, muscle damage and scars due to blockages, and other signs of severe coronary artery disease.
We ask you to take the following steps to prepare for a Cardiolite nuclear stress test:
We review your medications and let you know which ones to avoid.
The test takes 2-3 hours, so dress comfortably (wear walking shoes and gym clothes) and bring a light snack, drink, and something to pass the time, such as a tablet, cellphone, or book.
You can leave the office and return to your usual activities shortly after your stress test. We recommend drinking plenty of water to flush the radiotracer out of your body.
If you plan to board an airplane shortly after your stress test, the airport scanners may pick up traces of Cardiolite. Tell the technician administering the Cardiolite about your travel plans, and they’ll give you documentation for airport security.
Call Woodlands Heart and Vascular Institute in The Woodlands, Texas, or book an appointment online today if you experience heart symptoms (chest pain or pressure, shortness of breath, and dizziness) or have questions about an upcoming Cardiolite nuclear stress test.
