Cardiology is a branch of medicine concerned with the heart and diseases that affect it. Invasive cardiology is a special aspect of cardiology that uses invasive procedures to treat heart disease. These procedures generally require insertion of instruments through the skin and into the body to treat a problem - thus the term "invasive." Many of the procedures done in this exciting field can be lifesaving.

At the heart (no pun intended) of invasive cardiology is a procedure known as cardiac catheterization. This involves inserting a special thin tube called a catheter into or near the heart. In this procedure, the skin is first anesthetized with local anesthetic or "numbing" medicine. The catheter is inserted through the skin and into one of the blood vessels under the skin, usually in the groin area. Once the catheter is inside the blood vessel, it can be threaded or advanced through the vessel and into or near the heart. The catheter is usually watched as it's being advanced toward the heart with a special X-ray machine. The wonder of cardiac catheterization is what can be done once the catheter is in its place, in or near the heart.

The most common use for cardiac catheterization is when a blockage has occurred or suspected in the arteries that supply blood and oxygen to the heart. A blocked artery, supplying blood to heart, is the cause of heart attacks and angina. Angina is a chest pain or shortness of breath that occurs with lesser degrees of arterial blockage, that have not yet become severe enough to cause a complete heart attack. Long-term blockage in the heart arteries, also called the coronary arteries, can also weaken the heart and cause a condition called congestive heart failure. Heart failure is when the heart is too weak to pump enough blood to meet the body's needs.

During cardiac catheterization, contrast material or a "dye," can be squirted through the catheter and into the heart arteries. X-ray pictures of the dye can be taken as it goes through the heart arteries. This allows any blockages in these arteries to be seen. In many cases, if a blockage is seen, it can be fixed right away.

Fixing a blockage in a heart artery during cardiac catheterization involves what is called angioplasty. In most cases, a special tiny deflated balloon is placed into the blocked artery using a catheter. The balloon is placed into the center of the blockage and then inflated, which then opens up the blockage and restores blood flow and oxygen to the heart.

In many cases, this procedure is done as an emergency, when someone has or is suspected of having a heart attack. This procedure may also be used during a severe case of angina that won't go away, which is called unstable angina. Cardiac catheterization and angioplasty may prevent or lessen the permanent heart damage or even death, which can occur in these two conditions.

Invasive cardiology can also be used for several other conditions. In many cases, special instruments or tools are introduced through the catheter during cardiac catheterization to perform certain functions.
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