Cardiac catheterization carries a slightly increased risk when compared with other heart tests. However, the test is very safe when performed by an experienced team.

Generally the risk of serious complications ranges from 1 in 1,000 to 1 in 500. Risks of the procedure include the following:

• Cardiac arrhythmias
• Cardiac tamponade
• Trauma to the artery causing a hematoma
• Low blood pressure
• Allergic reaction to contrast medium
• Hemorrhage
• Stroke
• Heart attack

Considerations associated with any type of catheterization include the following:

• In general, there is a risk of bleeding, infection, and pain at the IV site.
• There is always a very small risk that the soft plastic catheters could actually damage the blood vessels.
• Blood clots could form on the catheters and later block blood vessels elsewhere in the body.
• The contrast material could damage the kidneys (particularly in patients with diabetes).

If a blockage is found, your health care provider may perform a percutaneous coronary intervention (PCI) to open the blockage. This can be done during the same procedure.