Myocardial Perfusion (Sestamibi) Scan



A Myocardial Perfusion Scan (also known as a Sestamibi Scan) is a test which examines the blood supply to the heart muscle (myocardium) non-invasively.

It is used to diagnose and to assess the severity of reduced blood supply to the heart due to blocked arteries.

The scan is divided into 2 parts. The 1st part looks at your heart muscle at rest, and the 2nd part looks at your heart muscle after a stress test (the stress test is an exercise that will either be walking on a treadmill machine or using a drug called Persantin).

The Procedure

1st part – Rest

A small cannula is inserted into a vein in your arm and a radioactive isotope (Sestamibi) is injected. After 45 minutes, we take pictures of your heart on a special camera. The pictures will take about 15 minutes. We need you to stay very still and breathe normally.

2nd part- Stress

After the first part, a stress test is performed either by walking on a treadmill, or by using a medication called Persantin injected through the cannula. Persantin is a chemical generally used to exercise patients when they are unable to walk on the treadmill.

During the stress test, your pulse rate and blood pressure will be recorded. You will be monitored closely with ECG leads attached to your body.

Just before the end of the exercise, a second dose of the radioactive isotope (Sestamibi) is injected. After the end of the exercise, we ask you to wait for 30-45 minutes and a second set of pictures are then taken.

Myocardial Perfusion Scan - 65 yr old man

Left: A myocardial perfusion scan of a 65 year old man with severe reduced blood supply to the bottom part of the heart. Right: Same patient after undergoing cardiac bypass surgery to restore the blood supply.
This scan is safe and non-invasive, often used to determine if an angiogram is necessary.

Side Effects

The stress test is safe and serious side effects are uncommon. You will be carefully monitored throughout the test. If however, you feel unwell within 24 hours of the test, you should consult your Doctor.

The radioactive isotope (Sestamibi) injection usually has no side effects. It is not related to the contrast used for X-rays and CT scans.

Please advise the Nuclear Medicine Technologist if you are pregnant or breast feeding, or unsure of your pregnancy status before commencing the procedure.

Patient Preparation

Food

Please do not eat for 4 hours before the test. Drinking plain water is allowed.

Please do not have caffeine containing food or drink (coffee, tea, coca-cola, chocolate) for 24 hours.

Clothing

You should wear comfortable, loose-fitting clothing for exercise and comfortable shoes for walking.

Special instructions for diabetic patients

Diet control: Fast as above.

On diabetic tablets: Take your diabetic medications and fast as above.

On insulin: Take half your morning insulin dose with a light breakfast 4 hours prior to the test. Please bring your insulin along.

Medications

Please consult your Doctor whether you should stop some of your medications before the test.