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 (image above), 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
(image above), 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 ICUS, 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.
Patient Preparation:
- No food or drink at least four (4) hours before the procedure.
- Take your medications with sips of water unless otherwise
instructed.
