How is a cardiac catheterization performed?

These procedures are performed at a hospital in the catheterization laboratory. The cath lab is equipped with an x-ray camera and a TV monitor (screen) on which the cardiologist views the heart and arteries.
The patient is given medications for sedation by mouth or by injection prior to starting the procedure. Sometimes, an IV (intravenous line) is placed into a vein in the patient’s arm. The IV allows the patient to receive fluids and medications easily. Children may receive more medications to help them relax.
The patient may be sedated but awake throughout the procedure or may be completely asleep under general anesthesia, depending on the procedure. The doctor will use a small needle to inject lidocaine, a local anesthetic, to numb the areas where the vessels will be entered. The procedure is typically painless. The heart itself does not contain pain receptors.

The femoral vein and artery in the groin -- near where the leg bends from the hip -- are the vessels doctors most commonly use to insert a catheter (a flexible tube that is smaller than the vessels) and thread it through the vessels to the heart, veins and peripheral arteries to perform the procedure. Sometimes a vein in the neck (internal jugular) or under the collar bone (subclavian vein) is used.
From this “access” point, the catheter is threaded through the veins and arteries to the heart. Because there are no nerves in the arteries, the patient will not feel the catheter or any pain during the catheterization procedure. A wide variety of specialized catheters in different sizes are available to be used for patients of all sizes – from newborn babies to adults.

The x-ray camera helps the physician guide the catheter to the heart. When the catheter is properly positioned, the cardiologist injects a contrast dye (radiographic contrast agent) through the catheter into the heart and its arteries. Most people do not feel the dye injection. However, some may feel a sensation of warmth in the chest, typically lasting only a few seconds. A few may feel lightheaded or nauseous.

When the x-ray beam passes through the dye, the arteries appear in black silhouette on a white background. The x-ray camera records a “movie” of the heart’s pumping chamber and arteries – a movie that can be recorded as a digital image or on 35mm film.
Cardiac catheterization procedures can help detect and/or treat heart problems. Here's how a cardiac catheterization procedure is performed:
  • A thin tube called a catheter is inserted through an artery (usually the femoral artery, in your groin).
  • Under the guidance of x-ray monitors, your healthcare provider gently guides the catheter through your blood vessels up toward your heart.
  • Once the catheter is in place inside your heart chambers or coronary arteries, your healthcare providers can create images of the heart and arteries. They can also directly treat problems with your heart if necessary.

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