Preparing for the procedure:
- Do not eat or drink anything after midnight the night before your procedure, except your morning medications and small sips of water.
- Insulin-dependent diabetics need to adjust their insulin doses accordingly.
- Oral diabetic medications should be held the morning of the procedure.
- Metformin (Glucophage) should be held the day prior to and the day of the procedure. Consult your doctor as to when this medication can be safely restarted.
- Prior to entering the hospital, notify your cardiologist if you have ever had a reaction to x-ray dyes, iodine, antiseptics, anesthetics, or any other drugs.
What to expect:
Diagnostic Cardiac Catheterization
After you arrive in the cardiac catheterization laboratory (cath lab), the staff will review the proposed procedure with you. They will ask you about the medications you are currently taking and when you last took your medications. A small IV will be placed in a vein in your arm to enable the administration of medications. You will be moved to a special table in the cath lab. Adhesive patches will be attached to your arms and legs so your electrocardiogram (ECG) can be monitored. You may be given a sedative to help you relax. Your groin or arm will be scrubbed with a special antiseptic solution and you will be covered with sterile drapes. This is done to prevent any infection at the puncture site. During the procedure, it is important that you keep your arms at your side, and not touch any of the sterile areas.
To perform the study, a catheter (small hollow plastic tube) will be inserted into an artery and/or vein in either the groin or arm. Before the procedure begins, the area will be anesthetized by the doctor. This will cause a slight sting or burning sensation which only lasts a few moments. As the catheter is inserted, you may feel some discomfort, although most people feel only pressure. If you have pain, please let your doctor know.
Under x-ray guidance, the catheter will be directed to the heart. You will not feel the catheter as it moves through the blood vessels or heart chambers. As the catheter enters the heart chamber, you may feel some extra heart beats. Pressure within the heart chambers will be measured, blood samples may be taken and x-ray dye (contrast) will be injected to study the size and contraction of the different chambers. When the dye is injected, a warm, flushing sensation may be felt over most of your body. This sensation will last for about 30 seconds. X-ray contrast will also be infected into each of your coronary arteries to look for blockages within these vessels. While these x-ray pictures are being taken, you may be asked to take a deep breath and hold it for about five seconds. You may be occasionally be asked to cough, as coughing helps clear the dye from your coronary arteries. If the study does not show significant blockages or if proceeding with intervention is not elected at this time, the catheter(s) will be removed.
If the diagnostic portion of the study shows blockages within your coronary artery (or multiple arteries), your cardiologist may choose one or a combination of methods to open the blockage(s). In general all of the methods involve placing small devices into your coronary arteries. A hollow tube (catheter) is positioned at the opening of your coronary artery or bypass graft. Through this, a small wire can be steered across the blockage. This wire acts as a rail over which various devices can be placed. At times these devices may temporarily interrupt the flow of blood through the atrtery being worked upon and chest pain can result. If you experience any chest pain or other discomforts during the procedure, please tell your cardiologist or the cath lab staff. We will make every effort to minimize your discomfort.
Post Procedure Care
At the end of the procedure, the catheters are removed, but the sheaths through which the catheters are introduced into the body are often left in place. This is because blood thinners are used during the procedure to minimize the risk that clots will form. Until the blood thinners have worn off, the sheaths cannot be safely removed. The sheath(s) may be removed in the cath lab or later in your room depending upon the status of the blood thinners.
Alternatively, special blood vessel closure devices can be used to enable the sheath to be removed immediately. If the catheterization was done from your arm, your doctor may close the artery and the skin with several stitches and a pressure dressing will be applied. Stitches are typically not needed when the groin is used. Pressure will be held for a variable amount of time depending on the dose of blood thinners used and whether or not a coronary intervention occurred.
After sheath removal, you will be required to lie flat in bed with your leg straight for a variable amount of time. If an artery closure device is used, this may require minimal bed rest. If pressure is used, you will remain at bed rest for about six hours. You may have your head raised about fifteen degrees and you may roll side to side. Your blood pressure and dressing will be checked frequently for the first 3 to 6 hours. If you feel a warm wet sensation in the groin area, apply pressure and call your nurse. The skin around the puncture site or incision may look bruised or slightly swollen. If you notice coldness or discoloration of your leg or arm, notify your nurse. It is common to feel some numbness along the inside of your thigh due to the local anesthetic that is used. You may have pain medication to relieve any discomfort that you may have.