What is it?
In cardiac catheterization (often called cardiac cath), the doctor puts a very small, flexible, hollow tube (called a catheter) into a blood vessel in the groin, arm, or neck. Then he or she threads it through the blood vessel into the aorta and into the heart. Once the catheter is in place, several tests may be done. The doctor can place the tip of the catheter into various parts of the heart to measure the pressures within the heart chambers or take blood samples to measure oxygen levels. Several different procedures can be done during and with a cardiac cath:
The doctor can guide the catheter into the coronary arteries and inject contrast dye to check blood flow through them. The coronary arteries are the vessels that carry blood to the heart muscle. This is called coronary angiography.
Angioplasty. In this procedure, the doctor can inflate a tiny balloon at the tip of the catheter. This presses any plaque buildup against the artery wall and improves blood flow through the artery.
Stent placement. In this procedure, the doctor expands a tiny metal mesh coil or tube at the end of the catheter inside an artery to keep it open.
Fractional flow reserve. This is a pressure management technique that’s used in catheterization to see how much blockage is in an artery
Intravascular ultrasound (IVUS). This test uses a computer and a transducer to send out ultrasonic sound waves to create images of the blood vessels. By using IVUS, the doctor can see and measure the inside of the blood vessels.
A small sample of heart tissue (called a biopsy). Your doctor may take out a small tissue sample and examine it under the microscope for abnormalities.
Why is it done?
Cardiac cath is used to help diagnose and treat several heart conditions:
Atherosclerosis. This is a gradual clogging of the arteries by fatty materials and other substances in the blood stream.
Cardiomyopathy. This is an enlargement of the heart due to thickening or weakening of the heart muscle.
Congenital heart disease. Defects in one or more heart structures that occur during fetal development, such as a ventricular septal defect (hole in the wall between the two lower chambers of the heart) are called congenital heart defects. This may lead to abnormal blood flow within the heart.
Heart failure. This condition, in which the heart muscle has become too weak to pump blood well, causes fluid buildup (congestion) in the blood vessels and lungs, and edema (swelling) in the feet, ankles, and other parts of the body.
Heart valve disease. Malfunction of one or more of the heart valves that can affect blood flow within the heart.