Gold standard catheter-based test for diagnosis of coronary artery disease
Coronary angiography is a test that uses a dye and special x-rays to show the inside of the coronary arteries. Narrowings or blockages of the arteries may limit the blood flow to the heart muscle and cause chest pain called angina. A catheter, a fine plastic tube, is guided into the heart to examine the coronary arteries. A special contrast dye that shows up on x-rays is injected into the arteries and allows the doctor to see any blockages or narrowings responsible for symptoms.
A coronary angiogram is a diagnostic test, not a treatment, and you will not notice any improvement afterwards. A coronary angiogram aims to provide important information about your heart and its blood supply, which is crucial in deciding on the best course of treatment. This may be conservative therapy (treatment with tablets), angioplasty (also called PCI, percutaneous coronary intervention, usually including insertion of a stent, a short metallic mesh) or coronary artery bypass grafting (CABG, a surgical procedure where the chest and leg blood vessels are sutured to the coronary arteries to "bypass" narrowings or blockages).
A coronary angiogram is a safe and routine procedure. The risk of serious complications is about 0.1 % (1 person out of 1,000) which in most cases is much less than the risk of leaving the patient without the necessary tests and treatment. This is an average figure for all cases, and the risk will vary depending on your circumstances; Dr Ruzicka will be more than happy to discuss any specific further risks or concerns with you. The risk involves the following:
Please bring all your medications with you on the day of the procedure. If you have diabetes, please follow the instructions given to you. If you take warfarin or other anticoagulants, you will be given advice for managing your medication before, during and after the procedure. You will also need to have a blood test at an anticoagulation clinic about a week after your angiogram to ensure your levels have stabilised. If you have diabetes and are taking metformin, you should stop taking the tablets the day before your procedure. Do not stop taking other diabetic tablets. You can drink water, clear tea and black coffee (without milk) up to 2 hours before the procedure. Milk, food, sweets, tea or coffee with milk can be consumed up to 6 hours before the angiogram. Chewing gum and smoking is not permitted on the day of the angiogram. Please take all your regular medication (except metformin) as usual with a sip of water. Please bring your dressing gown and slippers with you. You will be asked to put on a gown and paper pants during your admission. Your details will be checked and a name band placed on your wrist. The procedure is performed in the cath lab (catheter laboratory), a special x-ray room that looks like a small operating theatre. Before the procedure, Dr Ruzicka will again explain the test and answer all your questions prior to signing the consent form. A small cannula will be inserted into your arm.
There will be several members of staff in the room during the procedure, including Dr Ruzicka, nurses, a cardiac physiologist and a radiographer. You will be lying on your back on an x-ray table during a coronary angiogram. Your heartbeat will be monitored using electrodes and an ECG machine. The radiographer will move the table and camera to take the x-ray pictures. A local anaesthetic will be used to numb the wrist (less often groin), and usually, sedation will be given to help you relax. Once numb, a small tube, called a sheath, will be inserted into the wrist or groin artery. A catheter is then inserted through the sheath and guided through the artery until it reaches the heart and the origin of the coronary arteries. Low dose x-rays are used to guide the catheter into the right position. Once the catheter is in position, a special dye will be injected into the coronary arteries to outline them on an x-ray. When the test is over, the catheter will be removed, and the access site will be closed up and bandaged. The procedure usually takes about 30 mins.
After the procedure, you will return to the ward, where nurses will monitor your blood pressure and pulse. They will also check the wound and circulation of blood in the limb used for catheterization. After a period of rest in bed, you will be allowed to get up. Dr Ruzicka will explain the angiogram results and inform your GP about your further treatment. You will be able to eat and drink. It is important to drink plenty of fluid, which will help to flush the contrast dye from the system. Providing there are no complications, you will be allowed to go home approximately 2-3 hours after the procedure. If the test was performed via the wrist artery, the dressing could be removed in 24 hours. During the first 48 hours after your angiogram, you should not do anything strenuous to prevent bruising and bleeding. It is normal to feel some discomfort in the wound and a simple painkiller, such as Paracetamol, is usually helpful. You must not drive for 24 hours after discharge. Please arrange for a responsible adult to drive you home and stay with you for 24 hours. If the wound begins to bleed, you should press firmly over the area for 10 minutes.