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Cardiac Sestamibi Study


  • You have been referred for a Cardiac Sestamibi Study to assess the blood flow to your heart (the myocardium - muscle of your heart)

  • The whole test takes approximately 3-4 hours to do.

  • The test is done in two parts:

    • Resting Phase

    • Exercise Stress Phase

  • Upon arrival to the department, a small cannula is injected into a vein in your arm. This is the only needle required for the test.

  • A small amount of radioactive tracer called 99m-Technetium Sestamibi (99mTc-MIBI) (1) is injected into this cannula.

  • The tracer is then taken up into the muscle of your heart whilst you are in a relaxed state.

  • There are rarely any side effects with this injection.

  • Images of your heart in this Resting Phase is done approximately 15 – 45 minutes “after” the injection.

  • You will be connected to an ECG monitor and have your Resting images done. These take 20 minutes to perform and is painless.

  • You will be required to lie still whilst the Gamma Camera (2) takes a 3D image of your heart. This is called a SPECT/CT (3) image.

  • You are then required to either exercise on a treadmill or have a pharmacological stress test (for people who are unable to exercise).

  • A physician and nurse monitor your vital signs (taking your ECG and blood pressure) continuously to ensure a maximum level of safety whilst you exercise.

  • If you are unable to physically exercise and you are having the pharmacological stress test, you will be given a medication (Adenosine) that increases the blood flow to your heart. This simulates what occurs during physical exercise.

  • Again, a physician and nurse monitor your vital signs whilst you are receiving this medication.

  • You may feel some side effects with this medication. Side effects can range from; no effect, a warm feeling throughout your body (as if you’re exercising), headache, shortness of breath to chest pain. These side effects last only for a brief period and can be reversed immediately.

  • When you have reached your peak exercise, the physician injects (through your cannula) a second small amount of tracer (99mTc-MIBI).

  • After this second injection, you are free to eat, drink and take your medications as per normal.

  • Images of your heart in this Exercise Stress Phase is done approximately 15 – 45 minutes “after” the second injection.

  • You will be connected again to an ECG machine and have your Exercise Stress imaging done.

  • You will be required to lie still whilst the Gamma Camera (1) again takes a 3D image of your heart.

  • These Exercise Stress Images take 30 minutes to perform.

  • You receive a slight radiation dose by having a Cardiac Sestamibi Scan with SPECT/CT ~ up to 5.4 times your yearly background radiation (4).


Patient Preparation:

  • If you are pregnant, trying to fall pregnant or breast-feeding, you must inform our staff.

  • You must FAST from everything but water from midnight the night before your test.

  • You must NOT have any products that contain CAFFEINE for 24 hours (1 day) prior the test. This includes tea, coffee, soft drinks, chocolate, drinking chocolate, energy drinks, etc…

  • You must NOT take Viagra for 48 hours (2 days) prior the test.

  • You must NOT take Asasantin or Persantin 72 hours (3 days) prior the test.

  • Before stopping any other medications, confirm that it is safe to do so with your cardiologist or general practitioner.

  • If you have had prior imaging e.g. PET, Nuclear Scan, CT, MRI, X-Ray, Ultrasound, etc... please bring these with you.

  • Please also bring your referral and any blood results that you may have had done.

  • Please bring your medications with you on the day of the test.

  • Important Note: You cannot have this test if you have had a PET or Nuclear Scan within 24 hours prior to this test. If you have had Iodine-131 therapy, allow 4-weeks before having this test. Please ring to discuss booking options.​


Breast-Feeding Mothers: Once you have been given the tracer, you need to stop breast-feeding for two feeds. During this time, you need to express and discard your breast milk. You will need to bottle-feed your child during this period.

Diabetic Patients - Please follow these special rules:

  • Non-Insulin Dependent Diabetic Patients should NOT take their medication. Fasting is still required. Please bring your medication with you. Also, please bring a light sandwich with you.

  • Insulin Dependent Diabetic Patients can take HALF their insulin dose, with a light breakfast (e.g. toast and juice) at 6:00 am. Please bring your Insulin and a light sandwich with you. If you are unsure about these instructions, please contact us.

  • If you are on any other medications, please take these as normal unless your doctor specifically tells you to stop them. Your doctor may alter your medications for this test. Please bring a list of your medications for our records.

  • A list of medications that can effect a Stress Sestamibi Study can be found here...

  • Please wear comfortable clothing for exercise with NO metal buttons or underwire. For example a front opening shirt/blouse, pants, closed shoes or joggers.


(1) 99mTc-MIBI is the radioisotope technetium-99m bound to six (sesta=6) methoxyisobutylisonitrile (MIBI) ligands.

(2) A Gamma Camera is a device that detects gamma-rays (gamma-rays are very similar to x-rays) and does not emit any radiation..

(3) SPECT/CT imaging (Single Photon Emission Computer Tomography / Computer Tomography). CT does emit radiation.

(4) We all receive a yearly background radiation dose ~ 2.4mSv. Cardiac Sestamibi scan with SPECT/CT ~ 13mSv = 5.4 times yearly background dose.

value. quality care. convenience.

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