Coronary angiography is a procedure in which a contrast material that can be seen using X-ray equipment is injected into one of the arteries of the heart. This allows the doctor to view the flow of blood through the heart.
How is the test performed?
Coronary angiography is usually performed in conjunction with cardiac catheterisation. A mild sedative is given prior to the test to help the patient relax. The study is carried out in a laboratory by a trained cardiologist or radiologist and technicians or nurses. An intra-arterial line is inserted into one of the blood vessels in the arm or groin after the site has been cleansed and numbed with a local anaesthetic. A catheter is then inserted through the arterial puncture, usually from the groin. The catheter is carefully threaded into the heart using an X-ray machine that produces real-time pictures (fluoroscopy). Once the catheter is in place, contrast material is injected and pictures are taken.
Why is the test performed?
Coronary angiography is performed to detect obstruction in the coronary arteries, which can lead to heart attack. It may be performed if the patient has unstable angina, atypical chest pain, aortic stenosis, or unexplained heart failure. The test may also be performed for other reasons.
How to prepare for the test?
Food and fluid are restricted 6 to 8 hours before the test. The procedure takes place in the hospital and the patient is asked to wear a hospital gown. Sometimes, admitting the patient a night before the test is required. Otherwise, the patient will be admitted as an outpatient or an inpatient the morning of the procedure. The doctor explains the procedure and its risks. A witnessed, signed consent for the procedure is required. The doctor needs to be informed if the patient is allergic to seafood, if he has had a bad reaction to contrast material in the past, or if he is taking sildenafil (viagra), or if she is pregnant.
What happens during the procedure?
The patient is awake and able to follow instructions during the coronary angiogram. A mild sedative is usually given 30 minutes before the procedure to help him relax. The procedure may last from one to several hours. He may feel some discomfort at the site where the catheter is placed. Local anaesthesia will be used to numb the site, so the only sensation should be one of pressure at the site. Occasionally, a flushing sensation occurs after the contrast media is injected. Discomfort may also arise from having to remain still for a long time. After the test, the catheter is removed. The patient may feel a firm pressure at the insertion site, used to prevent bleeding. If the puncture is placed in the groin, he will usually be asked to lie flat on his back for a few hours after the test to avoid bleeding. This may cause some mild back discomfort.
What are the results?
An adequate blood supply to the heart is a normal finding with a coronary angiogram. Coronary angiography shows the following:
How many coronary arteries are blocked
Where are they blocked
The degree of each blockage
These results can help the cardiologist make decisions regarding treatment for the patient’s heart disease.