Your Heart Scan Explained

Information for patients having a myocardial perfusion scan and will tell you what a myocardial perfusion scan is and what will happen.

What will my scan tell my doctor?

The heart is a muscle that pumps blood around the body.  Like any muscle the heart needs a constant supply of nutrients and oxygen, which are carried to it by the blood in the coronary arteries.

Sometimes the blood supply to the heart can become partially blocked.  This blockage is due to the formation of a fatty deposit called plaque on the wall of a blood vessel in the heart.

This test looks at the blood supply to the muscle of the heart and may provide your doctor with useful information in your care.

Your test will take place over two separate days, as indicated on your appointment letter.

If the appointment clashes with another outpatient appointment or test, or you are unable to attend on this day, please contact this department as soon as possible. We can then reschedule the test and assign the appointment to another patient.

As the test involves small amounts of radiation, we ask that you are not accompanied by children under 18 or those who are pregnant. You may bring one adult with you to the department.

If you have mobility issues, are incontinent or claustrophobic please contact the department on the number provided.


Benefit and Risks of the Test

Everyone receives some radiation everyday from the radioactivity in the air, food we eat and even from space.  The amount of radiation in a nuclear medicine test is similar to your natural exposure over one year so the risks associated with it are low.

The main benefit of the test is making the correct diagnosis, so you can get the treatment that is right for you.  This benefit is far greater than the small risk from radiation.

What if I am pregnant or breastfeeding?

If you are pregnant or breast feeding, then you must inform us as soon as possible, because special arrangements need to be made.

What do I need to do before my scan?

If you are diabetic: on both days you should eat as normal, take any diabetic medications as you would normally and bring any diabetic medications with you to your appointment.

If you are not diabetic: on both days you must not have anything to eat for 4 hours before your appointment.


Caffeine and some medications will affect your scan.  The medications that you need to stop are detailed below.  Take all other medication as normal.

For 48 hours before your appointment you will need to stop:  Dipyridamole

For 24 hours before your appointment you will need to stop:

Aminophylline, theophylline or any other xanthines

For 24 hours before your appointment you must stop:

  • Caffeine (e.g. coffee, tea, drinking chocolate, cola, Lucozade, decaffeinated drinks). In addition please do not have orange juice to drink.


On the second day you may drink caffeinated drinks and take your medications as normal.

Please contact the department if further clarification is necessary.

If you do not comply with the advised preparations, your test will be postponed.

What should I do on the day of my scan?

Before arriving in the department

Ladies, you must wear the same bra on both days.

You must bring your repeat prescription list with you, as a record of your regular medications.

On both days, after injection and before the scan, you will be asked to eat a fatty meal, for example: a sausage roll, cheese sandwich, crisps or chocolate.

Please, therefore, ensure you either bring something with you to eat, or you can attend one of the coffee shops within the hospital where you can purchase one or more of these items.

After arriving in the department


On the first day you will be asked to lie on a bed.  You will be given a drug that will make your heart work a little harder, like when you exercise.  When your heart is working hard enough, a small amount of radioactive tracer will be injected into a vein in your arm.


On the second day you will be asked to sit in a chair, like when you rest.  Then a small amount of radioactive tracer will be injected into a vein in your arm.

Taking the pictures

On both days, about 1 hour after your injection we will take pictures of the blood supply to your heart.

The scan takes about 30 minutes and during this time you will be asked to raise your arms above your head (see photo).  The camera has an open design and supports are provided for your arms, so most people are able to tolerate the scan without discomfort.

The pictures will be checked before you are allowed to leave the department.  A small number of people need additional pictures which is perfectly normal.  The test takes between 3 and 4 hours in total.

When your test is reported, the pictures taken on both days are compared, so it is important you attend both appointments.

What do I need to do after my scan?

On both days after your injection and for the rest of that day:

  • Drink plenty of fluids and empty your bladder frequently
  • Flush the toilet twice (men should also sit down to urinate)
  • Wash your hands thoroughly after using the toilet

Contact details

If you have any questions about any of the information contained in this leaflet or if you do not understand these instructions, please telephone the department for assistance.

Department of Nuclear Medicine

Grantham and District Hospital:    01476 464777

Lincoln County Hospital:                 01522 573103

Pilgrim Hospital, Boston:                01205 445326