A coronary angiogram is an examination that makes use of a special dye and X-rays to help the doctor to see the inside of the blood vessels in the heart and to determine if there are any blocks or narrowing of one or more of its arteries. This is one of the procedures that can be classified into the group called cardiac catheterization. Typically the term catheterization can be used for any process during which a thin, long, flexible tube called the catheter is placed into any part of the body. A coronary angiogram is one of the commonest types of heart catheter processes. It can be considered a diagnostic and remedial option of treatment that can be availed of by people with ischemic heart problems that are a result of the narrowing of the coronary arteries. Angiographic images will display accurately how severely the arteries are blocked.
Usually coronary angiograms are done when a person suffers from a first attack of angina, or if the angina does not seem to go away as fast as it should, or is becoming worse. It is also used to check aortic stenosis, chest pain when all other examinations seem normal, heart failure or in the event that the patient has recently had a heart attack.
Preparation for a Coronary Angiogram
Before the examination, the doctor will explain to the patient the details of the procedures and the potential risks that could be involved. He/she will have to sign letter of consent before the procedure takes place. The patient is advised not to eat or drink any thing for a period of eight hours before the test is conducted and will probably have to be admitted into the hospital the previous night. The patient will be asked to remove all metal objects from the body including jewellery, spectacles, dentures hairpins etc. so that the images being captured are not affected.
How Does the Procedure Work?
Coronary angiography can be performed using x-ray with catheters, computed tomography or CT scanning or by using MRI scanning techniques
Equipment Used for Doing the Coronary Angiogram
The coronary angiogram requires special fluoroscopic x-ray equipment and techniques that can provide good quality images for the doctors to make the right diagnosis and determine the treatment to be carried out. The equipment will depend on the type of technique used for the coronary angiogram. The CT scanner is a cylindrical machine with a tunnel-like hole in the centre through which the examination table with the patient is sent into the scanner. The scanner is connected to a specialized computer that will be situated in another location, from where the technician operates the scanner and keeps track of the patient being examined.
How is the Procedure Performed?
The patient is given an injection that will relax him, but it will not put him to sleep. A particular spot in the groin or arm is chosen for the catheter to be inserted into the artery. This catheter will be inserted right up to the heart. This is done using the aid of the fluoroscope, which is a special X-ray viewing device. A special dye that contains iodine is injected through the catheter into each artery in the heart so as to make the arteries clearer in the X-ray. As the dye passes through the arteries plenty of x-rays are taken. EKG leads are also placed so as to monitor the heart beat rate and the rhythm of the heart during the test. The whole process takes about 25-30 minutes.
Once all the necessary images have been taken the catheter is removed and the doctor or nurse will ensure that direct pressure is applied on the spot where the catheter was inserted to ascertain that there will be no bleeding internally. In some cases the spot may have to be sutured. The patient will be asked to lie quietly on his back for a few hours after the procedure has been completed and he is taken back to the room.
Experiences Before and After the Coronary Angiogram
As the coronary angiogram is a test where there is a small surgical (invasive) process involved the patient may feel some slight discomfort when the catheter is being inserted into the artery. Because the patient is given a mild sedative he/she may not find it very disconcerting during the procedure, but may feel rather sore at the point where the catheter was inserted after the process has been completed. The patient could probably experience a warm flush and a metallic taste in the mouth as the dye courses through his body. He would also hear whining, buzzing and click sounds as the scanner revolves round him during the process. He may also feel tired of having had to lie still on his back for some time and he will also, as mentioned earlier, have to continue lying on his back for a few more hours after the procedure has been completed and he returns to his room in the hospital.
Benefits and Risks of Coronary Angiogram
One of the major advantages of the coronary angiogram is that it could in all probability help to avoid an impending surgery. Coronary angiogram helps the doctor determine the extent and the seriousness of the atherosclerosis in the arteries in the heart and determine the mode of treatment to be carried out. This procedure is believed to be the only examination that offers precise results regarding the severity of arterial blocks in the heart. Catheter angiogram offers very lucid and detailed images of the blood vessels in the heart and this is especially useful when a surgical operation is being thought about.
Though major dangers are rare, risks of a coronary angiogram, being an invasive surgical process can include a stroke, heart attack, irregular rhythm of the heart, allergy to the injected dye, excessive bleeding, infection, clotting of blood, exposure to radiation and even perforation of the heart or artery. In rare cases the tip of the catheter could separate substances from the inner lining of the artery through which it passes creating a block somewhere in the blood vessel.
Limitations will depend on the type of coronary angiogram being performed. In the case of catheterized coronary angiogram, the procedure cannot be done on those who have an allergy to the contrast dye, in which case some other similar substance will have to be injected to carry out the procedure.