Cardiac Catheterization 

Cardiac catheterization and angiography are tests in which
catheters (hollow tubes) are placed into the heart in order to
evaluate the anatomy and function of the heart and surrounding
blood vessels.  So much useful information can be obtained from
these tests that they are performed in virtually all patients being
considered for cardiac surgery or angioplasty. 

How is a catheterization performed?

The patient is brought to the catheterization laboratory and placed
on a special examination table.  After local anesthesia is given, a
catheter is inserted into blood vessels in the groin, arm, or neck.
(The catheter is inserted either through a small incision, or by
means of a needle-stick.  Sometimes, catheters are inserted from
more than one site.)  The catheter is advanced through the blood
vessels to the heart. 

Once in the heart, the catheter can be maneuvered to various
locations within the heart.  By attaching the catheter to a pressure
transducer, the pressures within various chambers of heart can be
measured.  Blood samples can be withdrawn from different locations
in order to measure the amount of oxygen in the blood (unusual
variations in blood oxygen can signal a "shunt," or abnormal blood
flow within the heart, often caused by congenital heart defects.)
Finally, by injecting dye through the catheter while a series of
rapid x-ray images is recorded, "movies" can be made of the blood
flowing through the cardiac chambers, or the through the blood
vessels surrounding the heart - a procedure know as angiography
(also called arteriography).  

Once the procedure is completed, the catheter(s) are removed.
Bleeding is controlled by placing pressure on the catheterization
site for 30 - 60 minutes.

What kinds of heart disease can catheterization
and angiography help to evaluate?

Cardiac catheterization and angiography can reveal vital information
about overall cardiac function, about the function of the individual
cardiac chambers, about the cardiac valves (whether they are too
narrow (stenosis) or too leaky (regurgitation)), congenital heart
defects, and about the location and severity of blockages in the
coronary arteries (the arteries that supply blood to the heart muscle).

What are some of the variations used with
catheterization and angiography?

Cardiac catheterization is often used therapeutically, that is, to deliver treatment for various heart problems. Therapeutic catheterizations include procedures to dilate stenotic heart valves, procedures to close atrial septal defects (i.e., a hole in the wall separating the left and right atria), and of course, procedures to relieve blockages in the coronary arteries (angioplasty and stent placement).  

What are the risks of having a catheterization or angiography? 

Cardiac catheterization and angiography are relatively safe, but
because they are invasive procedures involving the heart, several
complications are possible.  Nobody should have a cardiac
catheterization unless there is a reasonable likelihood that the
information gained from the procedure will be of significant benefit.

Minor complications of cardiac catheterization include minor bleeding at the site of catheter insertion, temporary heart rhythm disturbances caused by the catheter irritating the heart muscle, and temporary changes in the blood pressure.

More significant complications include perforation of the heart wall
(causing a life-threatening condition called cardiac tamponade),
sudden blockage of a coronary artery (leading to a heart attack),
extensive bleeding, stroke, an allergic reaction to the dye used
in angiography, vascular injury or renal failure.

Why Is A Cardiac Catheterization Done?

This test will help the doctor to evaluate the patient's cardiac 
condition related to: