Preparing for your Cardiac CT scan

Transcription

1 Preparing for your Cardiac CT scan This leaflet contains information about how to prepare for your CT scan and what to expect when you attend for your appointment. It is important that you read this leaflet carefully, even if you have had a CT scan before. If you are unable to attend your appointment, please telephone the department on What if I might be pregnant? If there is any possibility you might be pregnant, please telephone before your appointment. Your cardiologist has recommended that you have a Cardiac CT scan. This is to examine your heart and the arteries that supply it with blood. A cardiac CT is a specialised CT scan (computerised x-ray scan) that produces very detailed images of your heart and coronary arteries (and grafts, if present). The aim of the scan is to determine whether there is any narrowing or blockages within the vessels that supply the heart with blood by injecting x-ray dye (contrast) into a vein in the arm through a small plastic tube (cannula). Cardiac CT scans are performed as an outpatient examination in the CT department at the Royal Derby Hospital. In order to scan your heart it must be beating steadily with a rate below 70 beats per minute (ideally between beats per minute). It may be necessary to slow your heart rate before the scan can be performed. This is done by taking beta blocker tablets before you arrive in the CT department, and/ or by an injection which is given through the cannula immediately before the scan. If you are not already taking a beta blocker your cardiologist may prescribe a course of up to 3 days, twice daily doses. The final dose should be taken approximately 1 hour before your appointment. If you are on a beta blocker already (such as atenolol or bisoprolol) your cardiologist may ask you to take a higher dose before the scan. Your heart rate is monitored during the scan using an ECG. ECG leads will be attached to your chest and shoulders and your heart rate reading is shown on a screen.

2 Before you come to the department Is there any special preparation? Yes Do not smoke or eat any food for 4 hours before your appointment. Do not drink anything containing caffeine for 4 hours before your appointment (tea, coffee, fizzy drinks etc.) You can drink as much water as you need so that you do not become dehydrated. Do not take any stimulant medications for 12 hours before your appointment (decongestants, anti-histamines, painkillers with added caffeine). Do not take any erection medications (Viagra, Cialis, Levitra) for 72 hours (3 days) before your appointment. Take all your heart tablets, including any extra tablets prescribed for the scan. It is very important that these are taken otherwise it may not be possible to carry out the scan. Bring any inhalers/gtn spray that you use with you when you come for your scan. It is important that there is a record of your kidney function within 3 months of your scan. If you were given a blood test form in clinic please make arrangements to have your blood tested as soon as possible either at your GP surgery or at the Royal Derby Hospital (so that the result is available before the date of your scan). If you are known to have kidney problems a result within 1 month is required. Practice holding your breath before your appointment Take a moderate, comfortable breath in through your nose and then stop - do not breathe in or out, or move. Hold your breath for 15 seconds before breathing out gently. Keep practising until you are comfortable holding your breath for 15 seconds. It is vital you do not breathe when asked to hold your breath during the scan as the arteries around the heart are tiny and blurring of the images from breathing can make it impossible to assess the vessels and give a diagnosis Can I take my prescribed medication? Yes. You can take all your usual medications except stimulant or erection medication mentioned in the list above. Do I need to bring anything with me? Yes. Please bring GTN and inhalers, if you are prescribed them. You will be asked to change into a hospital gown. Some patients prefer to bring their own dressing gown with them. Please do not bring any valuables with you. 2

3 Can I bring a relative or friend with me? Yes, but we do not routinely allow friends or relatives into the scan room. You will remain responsible for any dependants (such as young children) accompanying you to your appointment. The staff will not be able to look after them while you are having your scan. When you arrive in the department Please go to the reception desk where your details will be checked and you will be asked to take a seat in the waiting area. Please arrive promptly at the time of your appointment, allow time for parking. Try not to be late, rushed or stressed as this will increase your heart rate. Before your scan you will be asked to remove your clothing and put on a hospital gown. You may also be asked to remove any jewellery, piercings or other items on or near your chest. You will be given a property bag for your clothing and personal items. Keep this with you at all times You will be taken to a quiet area to wait. A radiographer or radiographic assistant will weigh you, ask you some questions and will insert a cannula into your arm. A blood pressure cuff will be used to record your heart rate. Several readings may be taken. You may be given a beta blocker tablet if your heart rate is above 60 beats per minute. What happens during the scan? The scan is undertaken by a radiographer who will explain the procedure to you. Please ask any questions you might have. You will be asked to lie on the scanning table and to keep as still as possible. ECG leads will be attached to your chest and shoulders to monitor your heartbeat. You will be given a spray of GTN under your tongue to relax the coronary arteries and ensure clear images. You may be left to lie quietly for a short while your heart rate steadies. You will be asked to practice holding your breath (you can also practice this at home - see page 2). Some initial scans will be performed to locate your heart and measure the amount of calcification in the coronary arteries. If your heart rate is too fast for the cardiac scan, an injection may be given to slow it down. If the rate remains too fast, if the rate is irregular or if the initial scan demonstrates very heavy calcification of the coronary arteries the contrast injection will not be given and the examination is finished. If your heart rate is regular and below approximately 65 beats per minute the contrast injection will be given and the cardiac scan will be performed. The x-ray dose that you receive during the cardiac scan will depend on your heart rate - the slower the heart rate, the lower the dose. 3

4 The scanning table moves through the scanner and this will be the only movement of equipment that you will be aware of. The machine makes a whistling noise as it scans. During the scan the radiographer will be in a separate room. He or she will be able to see, hear and speak to you at all times during the procedure. The following medications may be used during the cardiac CT scan: X-ray contrast - a colourless dye which contains iodine. The injection is associated with a warm sensation or flush and a metallic taste which passes quickly. Metoprolol - a beta blocker which acts to slow the heart and lower blood pressure. It can be taken as a tablet or given as an injection. GTN spray - this relaxes the coronary arteries. It may cause a headache which usually passes quickly. Oxygen - this helps to relax the coronary arteries and eases breathing. Verapamil - this can be used to slow the heart rate when beta blockers cannot be used, e.g. in patients with asthma. Ivabradine - this can be used to slow the heart rate and would be prescribed by your cardiologist before the scan if required. Who will be present during the scan? The radiographers will carry out your scan and may be assisted by radiographic assistants. Student radiographers and other clinical staff undergoing training may also be present in the room. If you would prefer them not to attend, please let the radiographer know. What happens after the scan? After the scan has finished you will be taken to a waiting area and will be offered a cup of tea or coffee. Your pulse and blood pressure may be measured again. After approximately 15 minutes the cannula will be removed and you are free to leave. You may return to your normal activities and eat and drink as normal. You may drive. When will I get the results? The radiographer will not be able to tell you the results. Your results will be sent to your cardiologist or the healthcare professional who referred you for the CT scan. If you do not have an appointment to be seen in clinic, your cardiologist should write to you. If you have not heard from the hospital after 3 weeks please ring the hospital on and ask to speak to your cardiologist s secretary. 4

5 Are there any risks or after-effects? The examination involves exposure to x-rays, but the amount of radiation is kept to a minimum by sophisticated radiation dose controls on the scanner. Everyone is exposed to natural background radiation from the environment throughout their lives. This is normal and natural. One in three people develop cancer at some point in their lives due to many various causes, including natural background radiation. Medical x-rays give an additional dose and can slightly increase this risk. Any small increased risk of cancer, which might occur many years later, is outweighed by the benefit of having the scan performed so that a diagnosis can be made and treatment given. More information about the risk of exposure to x-rays can be found on the Public Health England website: Injection of dye (contrast) If you have an injection of dye (contrast) into a vein this may cause a mild allergic reaction. Very rarely, someone has an allergic reaction to the contrast injection which can be serious. If you do have this type of reaction, the doctors and radiographers know what to do to treat it. Is there an alternative to a CT scan? Your doctor has decided that a Cardiac CT scan would be the most useful in your case. The examination will help your doctor to assess you more fully and plan any further treatment that might be necessary. Cardiac CT cannot be performed on all patients. The following patients are usually not suitable: Patients whose heart rate remains too high to scan Patients with an irregular heart beat due to atrial fibrillation, atrial flutter or frequent ectopic or extra beats Patients with pacemakers and internal defibrillators Patients with a previous allergic reaction to contrast Patients who are unable to lie flat, with arms raised above their head (for a period of approximately 15 minutes Patients who cannot hold their breath for approximately 15 seconds or who are unable to understand/follow breath holding instructions Patients who weigh more than 180 kg (or approximately 28 stone) If you would like more information about alternatives including not having the test, please speak to your doctor or the healthcare professional managing your care. 5

6 Further information If you have any questions we will be happy to answer these on the day of the appointment or you can contact us on More information about having a CT scan can be found at the following websites: Do you need this information in another language? If you need this information in another language, dhft.imagingqualityteam@nhs.net Gdyby chcieli Państwo otrzymać niniejszy dokument w innej wersji językowej, prosimy skontaktować się z nami, korzystając z adresu poczty elektronicznej: dhft.imagingqualityteam@nhs.net ਜ ਤ ਸ ਇਸ ਜ ਣਕ ਰ ਨ ਕਕਸ ਹ ਰ ਭ ਸ਼ ਕ ਚ ਚ ਹ ਦ ਹ, ਤ ਕਕਰਪ ਕਰਕ dhft.imagingqualityteam@nhs.net ਤ ਈ-ਮ ਲ ਕਰ اگر آپکو یہ معلومات کسی اور زبان میں درکار ہوں تو برائے مہربانی ای میل کریں dhft.imagingqualityteam@nhs.net.dhft.imagingqualityteam@nhs.net ئەم گەر بۆ بکە ئیمەیڵ تکایە دەوێ تر زمانێکی بە زانیارییانەت Your feedback We hope you found the information in this leaflet helpful, but if it did not tell you what you needed to know we would like to hear about it. You can tell us what you think of this leaflet by completing a short survey at: P2108/1857/ /VERSION1 (CT Cardiac) Copyright. Any external organisations and websites included here do not necessarily reflect the views of the Trust, nor does their inclusion constitute a recommendation. 6