Cardiac Catheterization (Balloon Angioplasty, Stent, Atherectomy)
Cardiac catheterization is a test used to evaluate the heart and the coronary arteries. During a cardiac catheterization, a contrast material is injected into the coronary arteries to trace the movement of blood. The portion of the test involving the injection of contrast material and the tracing of blood is called coronary angiography.
To perform cardiac catheterization procedure, a thin flexible tube called a catheter is threaded through a blood vessel in the arm or groin and into the heart. Through the catheter, your heart doctor can measure pressures, take blood samples, and inject the contrast material. Movement of the dye through the heart’s chambers and blood vessels is visualized using an x-ray technique called fluoroscopy. Fluoroscopy provides immediate (“real-time”) visualization of the x-ray images on a video monitor and provides a permanent record of the procedure.
The purpose of cardiac catheterization is to determine whether the coronary arteries are diseased, and if so, identify the size and location of plaque that may have accumulated from atherosclerosis. This is generally done to determine the need for bypass surgery or angioplasty.
If the coronary arteries have blockages, your doctor can use the catheter to open them and restore normal blood flow to your heart. This is called percutaneous coronary intervention (PCI). The three common types of PCI are angioplasty, coronary stenting, and coronary atherectomy. These procedures can be done separately or in conjunction.
When a patient has a narrow artery, an interventional cardiologist will perform an angioplasty. Angioplasty may be done by attaching a small balloon to the catheter. Once the catheter has been placed in the correct position in the coronary artery, the balloon is inflated. The pressure from the inflated balloon presses the plaque against the wall of the artery to help blood flow more easily.
Stenting usually is done in conjunction with angioplasty. Once the plaque is compressed using angioplasty, a small expandable wire tube called a stent is inserted into the artery to hold it open. Reclosure of the artery is less likely to occur after angioplasty followed by stenting than after angioplasty alone. It is also common to use a type of stent coated with drugs. These drugs help prevent scar tissue from forming inside a stent. Studies have shown that these new stents are more likely to prevent restenosis than ordinary, non-coated stents.
Atherectomy may be done during cardiac catheterization to open a partially blocked coronary artery. Once the catheter reaches the narrowed portion of the artery, a cutting device, a whirling blade (such as a rotoblade), or a laser beam is used to remove the plaque.
Why It Is Done?
Indications for the procedure include:
- Angina that is not easily controlled with medication, that disrupts daily routine, occurs at rest, or recurs after heart attack
- Heart failure with suspected coronary artery disease
- Markedly abnormal stress test results
- Recurring chest pain with no known cause
The primary purpose of cardiac catheterization is to determine the severity of coronary artery disease (CAD), and if so, whether surgery or another type of procedure is needed to open the blocked blood vessels. Cardiac catheterization also can be used to treat CAD by opening the blocked vessels. The procedure is generally done only when there are symptoms of blockage or when your doctor has reason to believe there is a blockage and you may need treatment, such as bypass surgery or angioplasty (and stenting).
In addition, cardiac catheterization may be done to:
- Evaluate the pumping action of the heart and measure pressures inside the heart and the blood vessels.
- Determine whether a congenital heart defect is present and evaluate its severity. Sometimes coronary catheterization can also be used to correct the defect.
- Evaluate blood flow through the heart after surgery.
- Determine whether significant heart valvular disease is present, which may require surgery.
Cardiac catheterization may also be done in an emergency during a heart attack. A catheter is placed in the blocked coronary artery and a balloon is inserted to open the blocked area. In some cases, a small amount of medication to dissolve the blood clot may be injected through the catheter to dissolve the blood clot to help the blood to flow more smoothly.