This procedure is used by doctors to diagnose and treat problems affecting the heart. It is required when the doctor is suspecting blockage(s) in arteries supplying blood to the heart muscles. Those arteries are called coronary arteries.
The procedure enables the doctor to examine the coronary arteries and if required open the clog arteries to restore normal blood flow to heart muscles. At the same time, this procedure is used for diagnosis (angiography) and treatment (angioplasty) by opening or widening the restricted portion of the affected coronary arteries.
The blood flow to heart is reduced when coronary arteries are blocked due to the deposition of fatty materials along the inside wall of the arteries called atherosclerosis.
Angiography or angioplasty is also referred as Cardiac Catheterization.
Most commonly, it used for the following conditions affecting heart
- Diagnose by finding blood vessel blockages or narrowing. This is referred to as an angiogram or angiography
- Open the block artery by ballooning and stenting referred as Angioplasty
It can also be used for a number of reasons to diagnose or treat conditions affecting heart or blood supply
- Looking at the heart's pumping function
- Diagnosing birth defects affecting heart
- Measuring oxygen levels and pressure in different heart areas
- Getting a sample of heart tissue. This is referred to as a biopsy
- Looking for heart valve problems
Cardiac catheterization may also be used along with other procedure in the treatment of heart disease, including:
- Replacing or repairing heart valves
- Treating congenital (birth) defects and holes in the heart
- Opening narrow heart valves with a balloon valvuloplasty
- Preventing blood clots by closing off an area of the heart
It is considered as a very safe procedure.
Most people experience no complications with cardiac catheterization and the major risks are rare.
However, it is important to know the risks and they include
- Skin bruising
- Artery damage due tissue tearing in the artery or heart
- Heart attack
- Allergic reactions to medications or dyes used
- Kidney damage
- Development of blood clots
- Irregular heart rhythm
There are a few things patient needs to do to prepare for cardiac catheterization, such as
- Do not eat or drink anything 6 -8-hours prior to testing
- Try to relax
- Bring all medications patient regularly takes, including all over-the-counter medications and supplements to the hospital
At the hospital, patient will be asked to pass urine and remove all dentures and jewelry. A nurse will also check the pulse and blood pressure.
Usually, the procedure takes 30 minutes to a couple of hours to complete.
The patient is usually required stay overnight at the hospital.
The test is performed in a special room that has X-ray and imaging machines. The patient is usually awake during cardiac catheterization, but generally sedated. The patient is given local anesthesia to perform the procedure without causing any pain to the patient.
A very thin tube (about the thickness of the lead in a pencil) called catheter is inserted through one of the big blood vessel in the groin area or arm and guided all the way to the coronary arteries of heart. A small cut in the skin is made to allow catheter to go into the blood vessel.
A special kind of dye called contrast medium is injected through the catheter that makes it visible through the X-ray. The doctor sees the catheter and the affected portion (complete blocked or partially blocked area) of the artery on the screen.
The blockage is mostly due to Atherosclerosis (deposition of fatty material along the inside wall of the arteries) also called plaque. The plaque interrupts the normal flow of blood through the affected artery and thus causing symptoms of heart disease. The doctor can inflate a small balloon type of device from the tip of the catheter while inside the affected portion of the blood vessel. The ballooning is done for about 20-30 seconds a few time to press/ squash the fatty material along the inside artery walls to widen the passage in the artery. The balloon is deflated and then if required, the doctor using the same catheter insert a very small metallic mesh kind of device called stent at the site of fatty deposition. The stent stays in the affected area keeping the artery open and restore normal blood flow.
There are mainly two types of stent – one which releases micro quantity of drug to prevent blood clot formation – referred as drug-eluting stent. The other one does not release any drug – called as bare metal stent. The doctor decides, which stent is suitable in which patient.
During the procedure, patient usually does not feel pain as the catheter goes through the body, but if feel discomfort, let the doctor know.
After the procedure, the patient will spend few hours in a recovery area. Depending on why the procedure is done and the general health, patient may need to stay in the hospital or may be able to go home the same day.
Patient will meet with the doctor a few days after the test to discuss the results.
After the successful placement of stent, the patient is required to take some blood thinning medications on daily basis for several months to the rest of the life, depending on the condition of the patient.
If the test (angiography) shows that the patient need further treatment, the doctor will help to get this scheduled. In some cases, the patient may need to have this test repeated to either provide further treatment or to perform further diagnostic testing.