Nuclear Stress Test (MPI)

Test Preparation Guide

General Instructions:

Obtain a signed requisition from your referring healthcare provider and, if possible, email or fax a copy to our clinic.
Please arrive 15 minutes before your scheduled appointment with your signed requisition, if available, and your valid Ontario health card.
If applicable, bring a list of your medications and instructions from your referring healthcare provider.
We may request your height and weight to ensure our facilities are suitable for the required testing.
If you have mobility concerns, please ask your caregiver to accompany and assist you.
Please be considerate of other patients waiting for urgent healthcare appointments and provide at least 24 hours’ notice if you are unable to attend. A missed appointment will be charged a no-show fee, and your referring doctor will be notified.

Nuclear Stress Test (Myocardial Perfusion Imaging)

You should fast (except for water) for 4 hours before the test.
Insulin-dependent diabetics should take their insulin with a light meal 2 hours before the test.
Discontinue all caffeine products 24 hours before the test. This includes tea, coffee, decaffeinated tea and coffee, pop, chocolate, Tylenol 2 and 3, and medications containing caffeine.
Wear loose-fitting clothing, such as a T-shirt, track pants, and athletic shoes.
Bring a list of all current prescription medications. Check with your physician regarding the discontinuation of any heart medications, such as beta-blockers (e.g., Metoprolol or Atenolol) and calcium channel blockers (e.g., Diltiazem or Verapamil).
Do not take erectile dysfunction medications, such as Viagra, Cialis, or Levitra, for 48 hours before the test.
If you are pregnant, there is a possibility of pregnancy, or you are breastfeeding, nuclear medicine stress testing may not be appropriate at this time. Please consult with your physician.

MYOCARDIAL PERFUSION IMAGING consists of 2 parts, which may be completed in one or two days:

1. Rest Study: 1.5–2 Hours

For this portion of the test, the technologist will administer a small amount of radioactive tracer via intravenous injection. The tracer is carried by the bloodstream to your heart. There are no side effects associated with this injection. Approximately 15–45 minutes after the injection, the technologist will take pictures of your heart for approximately 20 minutes using a special gamma camera that detects the tracer. You may be sitting in a specially designed imaging chair or lying on a bed. It is important to remain very still while the pictures are being taken to avoid blurring the images.

2. Stress Study: 2–2.5 Hours

For this portion of the test, ECG electrodes will be placed on your chest to monitor your heart rhythm throughout the test. An intravenous line will also be placed in your arm or hand. You will begin exercising on a treadmill, during which your heart rate and blood pressure will rise. These are normal responses that will be closely monitored using your ECG.

If you are unable to exercise adequately on a treadmill, similar results can be achieved using a drug called Persantine. Persantine mimics the effects of exercise by dilating the blood vessels of the heart, allowing increased blood flow.

Once you have reached your maximum level of exercise, the technologist will administer a small amount of radioactive tracer, and you will continue exercising for an additional 1–2 minutes. If blood flow to the heart is limited due to coronary artery disease, the amount of tracer reaching your heart may be reduced. Following the stress test, the intravenous line will be removed.

It is very important that another set of pictures is taken after the stress test to compare with the resting images and assess the blood supply to the heart at rest and during stress (exercise). Once the stress test is complete, you will wait approximately 15–45 minutes before imaging begins. The waiting time may vary depending on individual characteristics to optimize image quality. The technologist will advise you how long you will need to wait before imaging.

After the Test

You will be able to return to your normal activities when the test is complete, unless your physician or technologist advises otherwise. You can drive after the test. If you are travelling by plane or train, or crossing the border within one week after your test, please inform the technologist.