Cardiac catheterization, also known as a coronary angiogram, is an invasive diagnostic procedure that assesses the heart’s arteries, valves, and contractility (squeezing strength of the heart muscle) as well as the pressures generated within the heart and lungs. Tiny tubes called catheters are inserted through the groin or arm vessels under X-ray (fluoroscopic) guidance while you lie flat. Dye is injected into the heart arteries to determine if there is blockage and into the main pumping chamber of the heart to determine its strength, known as the “ejection fraction”. Local anesthesia is given at the insertion site and oftentimes a light conscious sedation is used. If the groin approach is used, you may need to lie flat for several hours to allow the puncture site to heal. Catheterizations are performed both on inpatients and outpatients.
Following cardiac catheterization, your physician may advise medication, balloon angioplasty, or surgery.
Percutaneous Transluminal Coronary Angioplasty, known as PTCA, is the procedure that uses a balloon to open a blocked artery. After a thin wire is passed across a blockage, a balloon-tipped catheter is inflated, flattening the plaque against the artery. Blood thinners are given during the procedure, and the tiny tubes inserted in the groins, called sheaths, may not be removed for several hours until the blood thinners lose their effect. Because there is a small risk of needing emergency surgery for failed angioplasty, the procedure is performed at the hospital on an inpatient basis.
Unfortunately, the angioplasty technique is plagued with up to a forty percent (40%) recurrence of the blockage, often within the first six months. This recurrence is known as restenosis. Coronary stents are small metallic scaffolds, often balloon -mounted, that are permanently placed across a blockage. Stents are known to reduce restenosis to less than twenty percent (20%) in many cases.
Rotational Atherectomy, or Rotablator®, is often done in conjunction with PTCA and stenting. A small high-speed drill is passed over a wire to pulverize plaques into microscopic particles. Rotablator® is particularly useful for small, diffusely diseased arteries, and arteries with heavy calcium deposits. Directional Atherectomy, called DCA, uses a small cutting blade to shave plaque into a chamber. The debris is then removed from the body. Large, bulky blockages respond well to DCA.
Intravascular Ultrasound, or IVUS, is essentially an echocardiogram performed on a catheter placed within the artery. It gives information on vessel size, plaque composition and percent stenosis. Intravascular ultrasound is used to ensure the proper seating of stents against the arterial wall.
Peripheral angioplasty, called PTA, is the balloon technique applied to the peripheral arteries. Peripheral stents are placed in selective locations. Renal artery angioplasty and stenting are used for treating blockages of the kidney arteries. This may help preserve kidney function or decrease the high blood pressure caused by these blockages.