Diagnostic Imaging Services

Bayhealth Diagnostic Imaging Services, including facilities at Kent General Hospital, Milford Memorial Hospital and affiliated locations, represents one of the region's most sophisticated imaging centers.

Cardiac Catheterization

Cardiac catheterization is a means of evaluating your heart and coronary arteries. A special dye (called contrast material) is usually injected into the arteries to trace the blood's flow through the heart. The portion of the test using contrast material to trace blood flow is called coronary angiography.

How It Is Done
A thin flexible tube (catheter) is threaded through a blood vessel in your arm or groin and into your heart. Through the catheter, your doctor may measure pressures, take blood samples, and inject contrast material into the coronary arteries or heart chambers. The doctor monitors blood flow to see whether the coronary arteries are reduced or blocked. Arteries can become narrowed when fat (cholesterol) and calcium accumulate along the lining, forming plaque.

Purpose
Cardiac catheterization pinpoints the size and position of plaque that may have built up as a result of atherosclerosis. This is generally carried out to decide if a bypass surgery or angioplasty is required.

If there are blockages, your doctor can use the catheter to complete a percutaneous coronary intervention (PCI), opening the blockage and restoring normal blood flow. The three common types of PCI are angioplasty, coronary stenting, and coronary atherectomy. These procedures may be performed separately, or in combination.

  • Angioplasty. To treat coronary artery disease (CAD), angioplasty involves attaching a small balloon to the catheter. Once the catheter is guided appropriately into the artery, the balloon is inflated. The resulting pressure then presses the plaque against the wall of the artery to ease blood flow.
  • Stenting. Stenting is generally completed in tandem with angioplasty. Once the angioplasty has compressed the plaque, a small expandable wire tube known as a stent is sometimes inserted into the artery to hold it open. Reclosure of the artery is less likely after angioplasty when it is followed by stinting.
  • Atherectomy. Atherectomy is another procedure often performed during cardiac catheterization to improve blood flow within a partially blocked artery. Once the catheter reaches the artery's narrowed passage, a cutting device, a spinning blade (such as a rotoblade), or a laser may be used to remove the fat and calcium buildup.

How to Prepare
Inform your doctor if you:

  • Are allergic to shellfish (shrimp, scallops, lobster), the iodine used as the contrast material for X-ray tests, or any other substance that contains iodine. You should also tell your doctor if you have ever had a serious allergic reaction (called anaphylaxis) from any substance (such as the venom from a bee sting).
  • Are taking any medications, including sildenafil (Viagra). This test may require the use of nitrate medication, such as nitroglycerin, that can cause a serious reaction if you have taken sildenafil (Viagra) within the previous 48 hours.
  • Have any bleeding problems or take blood-thinning medication.
  • Are or might be pregnant.

You will be asked to sign a consent form before the test. Consent for cardiac catheterization is a two-step process. The first step is to consent to the testing, or diagnostic, portion of cardiac catheterization, including a coronary angiogram to evaluate the coronary artery blockages.

Step two is consenting to the treatment, which may include a PCI to open your blocked arteries, depending on the results of the diagnostic phase. Take this opportunity to talk with your doctor about any concerns you may have about how the procedure is performed or the risk involved. Also, be sure you clearly understand what treatment will be recommended if a blockage is found.

If you are not already hospitalized, you will probably be admitted the day before your test. Sometimes the procedure can be completed without an overnight stay. If so, you should know where you need to go and when to arrive. Someone will need to pick you up, since you will not be able to drive following the test. Wear comfortable clothes and pack an overnight bag in case you need to be admitted to the hospital after the tests. You should also leave any jewelry or other valuable items at home.

You will have a physical examination, some blood tests, an electrocardiogram (EKG), and possibly other heart tests or a chest X-ray. If you are taking any medications, ask your doctor regarding advisability of taking them on the day of your test.

Do not eat or drink for 6 to 12 hours before the test. About an hour before the procedure, you may be given a sedative to help you relax. It will not put you to sleep, since it is important that you be awake to follow instructions during the test.

Before the test, remove any necklaces, bracelets, rings, or other jewelry. You should also remove nail polish from your fingernails and toenails to permit better observation of the blood circulation in your fingers and toes. Certain areas on your arms or groin will be shaved to prepare these sites for possible insertion of the catheter. Be sure to empty your bladder completely just before the test. Before the procedure starts, you may want to ask for cushions or pillows so you'll be as comfortable as possible.