A heart CT scan uses a series of X-rays to diagnose vascular pathologies of the heart, lungs, mediastinum (area around the heart) along with some bone pathologies in this region. In this case, a contrast agent is injected intravenously to highlight the area being examined.
30 to 45 minutes
- It is highly recommended that you avoid heart stimulants such as cigarettes, cola, tea, coffee as well as chocolate or any other caffeine-containing food 24 hours before your appointment, as the scan captures images between heart beats and a regular rate makes the imaging process easier.
- You must be in a fasting state for at least 3 hours before the exam.
- To ensure the exam is successful, a medication may be prescribed to slow your heart rate.
- Medications such as Viagra® or Cialis® must be stopped 48 hours before and 48 hours after the appointment.
- A blood test to evaluate the kidneys' effectiveness at eliminating the contrast agent is required for this exam.
- You should plan to arrive 2 hours before the appointment time.
- During the appointment, you should advise staff whether you have allergies or are diabetic, as you will receive additional instructions.
- For women of childbearing age, it is important to advise the technologist if you might be pregnant, as X-rays are harmful to the fetus.
- Breastfeeding women must stop breastfeeding for a period of 48 hours.
- Remove earrings, hearing aids, eyebrow piercings, hair clips and wigs.
A medical imaging technologist will position you on your back and place three electrodes on your chest. The areas where the technologist places the electrodes may be shaved to ensure good adherence. After taking your blood pressure, the technologist will insert an IV catheter in order to inject the contrast agent. Your arms will then be positioned above your head. The injection of the contrast agent can cause a sensation of warmth, a false need to urinate, or a metallic taste in your mouth. These effects only last a few seconds and then immediately disappear. Depending on your blood pressure, you will be given a dose of nitroglycerin to optimize imaging of the coronary arteries. Shields are then placed over the genitals and breasts (for women) to prevent these areas from being exposed unnecessarily to radiation. You will be given instructions about when to hold your breath as the images are acquired.
- A radiologist will analyze the exam and send the report to your treating physician.
- An allergic reaction may occur, but the team is prepared to quickly react to this possibility.
- The nitroglycerin may cause a temporary headache that will subside with food.
- You will have to drink a lot of water to eliminate the contrast agent.
- For diabetics, a second blood test may be required 48 hours after the exam. These patients will receive additional instructions about restarting their medication.