Nuclear Cardiology

Myocardial Perfusion Imaging (MPI), is also known as a Nuclear Medicine Cardiac Stress test. It is done to determine how well the coronary arteries are delivering blood to your heart. We will be able to determine if a particular artery is blocked and therefore limiting the circulation to your heart. It will also assess the heart wall motion and ejection fraction, and determine if the heart muscle has been damaged from a previous heart attack. All of this information will assist your physician in making management and treatment decisions.

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Test Preparation

• If taking erectile dysfunction medications (specifically Viagra, Levitra, Stendra, Cialis or Muse) for pleasure, please discontinue for 5 days prior to this test. If used for other reasons, please consult your doctor for approval to temporarily discontinue for 96 hours prior to this test.
• Consult your doctor for approval to temporarily discontinue any Beta blockers or Calcium channel blockers 48 hours prior to this test.
• Consult your doctor for approval to temporarily discontinue any medications containing caffeine i.e. prescribed Tylenol/Lenoltec 1, 2, or 3 for 12 hours prior to this test. There is no caffeine in over-the-counter Tylenol.
• Please do not stop any medications without your doctor’s approval. If your referring physician did not provide instructions to stop your medication, we will continue to do the test based on what your referring physician requested.
• No caffeine or decaffeinated products 12 hours prior to your test (no tea, herbal tea, coffee, decaf coffee, chocolate, soda pop or medications containing caffeine).
• No food 3 hours prior to your test. You can continue to drink plain water during the fasting period. For those with diabetes, hypoglycemia, or patients with low blood sugar, a light meal is allowed (for example, dry toast, banana with juice).
• Do not apply any body lotion or oil to your skin on the day of the test.

What to Bring

• Bring snacks to your appointment. Your technologist will let you know when you can begin eating again during your appointment.
• Wear loose fitting, comfortable clothing (athletic clothing) and running shoes.
• Please bring your health card with you to your appointment.
• If you are not covered through OHIP, please bring any insurance information.
• Bring a list of your current prescription medications and vitamins/supplements.

Other Notes

• If you do not speak or understand English, please ensure you can bring someone to your appointment that can communicate and understand English, and that they can stay for the full duration of your appointment.
• Please let us know if you are experiencing any respiratory or gastrointestinal signs/symptoms and do not feel well enough to attend your appointment.
• If you use a wheelchair, are pregnant, or there is a chance of pregnancy or breastfeeding, please call us.
• If you have had a nuclear medicine test at another facility in the past week, please also call us.

Arrival Time

• Please arrive 15 minutes prior to your scheduled appointment to complete some paperwork and check-in.
• If you late cancel or no show for your appointment, you may be charged a cancellation fee.

During the Test

• At your appointment, an IV line will be inserted in your arm and a radioisotope tracer will be administered. This is not a contrast dye. There are no known side effects or allergic reactions. You may or may not experience a momentary metallic taste/smell when the tracer is injected. Following this, there will be a waiting period of at least 45 minutes before capturing an image of the heart.
• Subsequently, you will undergo a stress test (either exercise or a pharmacological approach with Persantine) based on your doctor's referral (note that on occasion, an exercise stress test may need to be shifted to a pharmacological approach, or vice versa). Another dose of the radioisotope tracer will be administered during the stress test, followed by an additional waiting period lasting 45 -75 minutes. After this period, a final image of the heart will be taken. The entire testing process typically spans between 3-4 hours. Please be aware that the waiting periods after each injection may vary depending on our clinic schedule.
• You will be regularly monitored during your appointment. Should you have any symptoms during the stress procedure, our medical staff and physician will take the necessary measures to assess and treat your condition. Please inform us if you experience any side effects or discomfort at any time throughout your appointment.

After the Test

• After your appointment, you are encouraged to drink 3-4 cups of fluids and you may return back to your normal activities and resume your medications as normal unless your physician tells you otherwise. The radioactive tracers will stay in your system between 24-48 hours. Drinking lots of water will help your body flush it out faster. 
• If you are travelling by plane, train or crossing the border within 7 days after your test, please inform the technologist.
• Your referring physician should receive your results in approximately 7-10 business days.

Contact Details

• You can reach us at 1-877-564-5227, extension 2. Our call centre is open Monday to Fridays from 8am-6pm, and Saturdays from 9am-5pm. If you have a next-day or same-day appointment, you can reach us outside of our call centre hours, by pressing extension 7.

Frequently Asked Questions (FAQ)

Can I access my medical images and reports through PocketHealth?

• Yes, you can access your medical images through PocketHealth. However, written reports are currently not available through the platform. If you would like a copy of your report, please reach out to the referring doctor.

How do I get to the clinic?

• For directions to the clinic and the nearest major intersection, please see Locations & Directions

Can I proceed with the appointment if I am on oxygen?

• We’ll need to understand why you’re on oxygen to determine if we can proceed. Depending on the underlying condition, we may not be able to proceed with the appointment.

Is it okay to wear body lotion or perfume for my appointment?

• Please do not wear any scented products to the appointment.

What if I've misplaced my health card?

• You can still attend your appointment if you bring a printed copy, photocopy, or photo of your health card.

Will there be any out-of-pocket costs?

• Most services, including Specialist Consults and diagnostic testing, are covered by OHIP.
• If you're paying privately, some insurance providers can be billed directly.
• In other cases, you may need to pay upfront and submit the receipt to your insurance.
• If you do not have OHIP coverage, out-of-pocket payment is required.

Do you have wifi at the clinics?

• Yes, we have wifi available.

Where can I provide feedback or file a complaint?

• You can provide feedback or file a complaint via email at [e-mail] or by visiting our website here.

Can you provide a doctor's note that can send to my employer?

• Yes, we can provide work letters on the day of your appointment. Please ask the reception team.

What is the purpose of this test?

• The purpose of your test is to determine & diagnose if you may have any coronary artery disease or guide your physician in the treatment plan of any heart disorders.

How much radiation is involved?

• Total radiation exposure is somewhat equivalent to a typical Chest CT Scan.

Is this test safe?

• The reason you are having this procedure is because your referring physician has determined this procedure is important to help diagnose any cardiac disease. Nuclear medicine procedures require the referral of your physician who is familiar with your medical history and can best assess the benefits vs. risks of the procedures. Nuclear Medicine procedures involve an intravenous injection of a radionuclide (a.k.a. radioisotope, radiopharmaceutical) which will localize in the target organ that we will image.

Is this the same as a contrast dye?

• The radioactive tracers are not dyes and neither considered a contrast.

Does the radioactive tracer have any side effects?

• There are no known side effects or allergic reactions. You may or may not experience a momentary metallic taste/smell when the tracer is injected. You will be closely monitored by our skilled technologists and physician during the test. If you do not feel well at any point during your procedure, please notify the medical staff.

Am I able to drive after the test?

• This test does not affect your ability to drive. You may resume your normal activities after the test. (e.g. go to work after). KMH does not provide sedatives to patients for this test. However, if your referring physician prescribes any sedatives that will impair you from operating any motorized vehicle, you are required to have a designated driver. If you feel unwell after your procedure is complete, please notify any medical staff to assess your condition.

Will it hurt?

• You will receive an intravenous catheter (IV) which will remain in your hand/arm for several hours. This may cause a bit of discomfort. You are encouraged to apply pressure for 3-5 minutes when the IV is removed to minimize any bruising. The administration of Persantine or other medications may cause a bit of discomfort. The administration of the radiopharmaceutical will not cause you any pain or discomfort. If you have any pain or symptoms during your appointment, please notify any of the medical staff right away.

Am I okay to be around children?

• You are encouraged to limit holding infants or children under the age 1 for long periods for the next 24 hours. You are safe to be in the same house with an infant and also safe to help with quick tasks such as changing diapers.

How long will I be on the treadmill if I have an exercise stress test?

• For exercise stress tests, the length of your exercise is dependent on your stress tolerance and health. You are encouraged to exercise for as long as you can until you feel fatigued or aim to reach at least 85% of your Target Heart Rate. The stress procedure follows the 7-stage Bruce’s Protocol for a maximum of 21 minutes. Each stage lasts for 3 minutes and the treadmill increases in speed and incline for every stage.

How long does the tracer stay in my body?

• Technetium-99m has a physical half-life of 6 hours. Once it is administered in your body, your biological half-life will also help to excrete the radioactivity. Your system should be clear of any radioactivity 24-48 hours after the administration of Tc-99m.

Would I be able to take my regular medications?

• Please consult your physician regarding discontinuation of any medications. Please do not stop any medications without your doctor’s approval. If your referring physician did not provide instructions to stop your medication, we will continue to do the test based on what your referring physician requested.

What is the name of the radioactive tracer used?

• The name of the radioactive tracer is Technetium-99m.

Does smoking interfere with a nuclear medicine test?

• Smoking does not interfere with a nuclear medicine test, except in cases where you are scheduled for a PET appointment on the same day. If you are wearing a nicotine or nitroglycerin patch, you will be asked to remove it upon arrival at the clinic; there is no need to remove it beforehand. Similarly, alcohol and/or cannabis use does not interfere with a nuclear medicine test. However, patients are advised to follow all safety and transportation regulations and maintain sobriety as needed for their visit.

Does a shellfish allergy interfere with a nuclear medicine test?

• A shellfish allergy does not interfere with a nuclear medicine test.

Why does caffeine need to be discontinued 12 hours prior?

• If you have consumed any caffeine prior to your test, we may not be able to do the stress test portion. This is because caffeine acts as is a vasodilator (opens the blood vessels) and therefore, may interfere with the results of the test.

Why do we also ask female patients to get approval to discontinue Viagra, Levitra, Cialis, etc?

• Medications such as Viagra can be prescribed for a wide range of things for both men and women. For example, Tadalafil (i.e. Cialis) can be used to treat erectile dysfunction, enlarged prostate, and also pulmonary hypertension. The stress test will have to be rebooked if these medications have been consumed.

What are the two different kinds of stress tests?

• There are two types of stress tests: exercise stress tests, where patients exercise on a treadmill during the test, and pharmacological stress tests, which use the medication persantine to dilate the coronary arteries, mimicking the effects of exercise.

Why do some stress tests need to be carried out over 2 days?

• Stress tests can be completed in either one or two days, depending on the patient's weight. Patients under 240 lbs are typically scheduled for a one-day test, while those over 240 lbs are usually booked for a two-day test. However, there is an exception - if your appointment is at either of the Kitchener or Scarborough clinics, the cutoff is 300 lbs instead of 240 lbs. For two-day tests, a nuclear radioisotope is administered on both days, but the actual stress test is only performed on the second day. On this day, patients will undergo either an exercise stress test, where they will exercise on a treadmill, or a persantine stress test, where the medication persantine is used to dilate the coronary arteries to simulate the effects of exercise. Not all patients will need to exercise on the treadmill if they are booked for a persantine stress test.

What should I do if I'm claustrophobic?

• Claustrophobia is a common concern for this test. If you experience claustrophobia, please let the technologist know. There are ways that the technologist can position you and the imaging camera as to alleviate feelings of claustrophobia (ie. lying on your stomach for imaging rather than on your back). If you suffer from severe claustrophobia, we recommend speaking with your referring physician, who may prescribe a sedative to help you feel more comfortable. If a sedative is prescribed, please bring it with you to your appointment, as the technologist will inform you when to take it. You must also arrange for a designated driver to take you home after your test. Our care team is here to support you—we can walk you through the procedure step-by-step and will closely monitor you throughout the test. If you feel unwell at any time, please let our medical staff know right away.

Can I take Gravol prior to my appointment?

• Please refrain from taking Gravol 12 hours prior to your appointment as it has trace amounts of caffeine in the coating.

Can I drink sparkling water during the fasting period?

• You can drink sparkling water, as long as it is plain sparkling water.

Can I work out or exercise prior to my test?

• Yes, you can work out or exercise prior to your test.

Are there any special considerations if I have a Left Branch Bundle Block (LBBB)?

• Yes. Individuals with a LBBB will need to do a persantine stress test. If you have a LBBB and you are booked in for an exercise stress test, a doctor will need to approve switching you to a persantine stress test. Please let us know if you have a LBBB and we can help arrange for a new referral from your physician.

Can I brush my teeth with toothpaste prior to my test?

• Yes, you can brush your teeth with toothpaste prior to your test.

Can I chew gum prior to my test?

• Yes, you can chew gum prior to your test.

Can I get a flu shot prior the appointment?

• You can get a flu shot prior to the appointment. This will not have any affect on the test results.

Can I take antihistamines prior to the appointment?

• Yes, antihistamines are ok to take before your appointment. This includes, for example Benadryl, Reactine, Aerius, Claritin, Allegra and Blexten.

Will metal objects like jewelry, dental work, or implants affect the nuclear cardiology test?

• No, metal objects will not affect the nuclear cardiology test. You do not need to remove any metal items unless they interfere with the imaging equipment's view of your chest.

Will I be lying on my back for the test?

• During tests at Scarborough and Kitchener locations, depending on the images being taken, you may be asked to lie on your back or on your stomach. At all other locations, you will lie on your back. If you cannot lie still on your back or your stomach on the exam bed for scanning, please call us.
• If you are claustrophobic, you may have the choice of lying on your stomach. You can speak to your technologist about this during the appointment.