What Is the Difference Between Left and Right Heart Catheterization?

Cardiac catheterization, also known as cardiac cath or heart cath, is a procedure to examine the functioning of the heart.

A thin, narrow tube called a catheter is inserted into a blood vessel of an arm or a leg, and is guided to the arteries of the heart using an X-ray camera. The doctor then injects contrast dye into the blood vessel through the catheter to get an X-ray view of the valves, arteries, and the heart chambers.

Right heart catheterization goes through the artery, while left heart catheterization goes through the veins.

• Catheterization of the left side of the heart is performed by passing the catheter through the artery.
• In catheterization of the right side of the heart, the catheter passes through the veins.

Cardiac catheterization is done for diagnosing the following heart conditions:

• Atherosclerosis: Deposits of fat, cholesterol, calcium, and clotting materials, known as fibrin in the innermost layer of arteries (endothelium), which results in clogging of the arteries.
• Cardiomyopathy: Enlargement of the heart due to thickening or weakening of the heart muscle.
• Congenital heart disease: Defects in one or more heart structures formed during fetal development.
• Heart failure: A condition in which the heart muscles become too weak to pump blood well, leading to congestion in the blood vessels and lungs.
• Heart valve disease: Failure of one or more heart valves, leading to reduced blood flow within the heart.
• To determine the extent of coronary artery disease (CAD) in patients with confusing clinical presentations

Patients with the following conditions shouldn’t undergo cardiac catheterization:

• Severe uncontrolled blood pressure
• Severe anemia
• Kidney failure
• Allergic to contrast dyes
• Stroke
• Heavy bleeding in the stomach and intestine
• Abnormal changes in the electrolytes
• Severe coagulopathy (impaired ability of the body to clot)
• Ventricular arrhythmia (irregular heartbeat in the heart chamber)
• Untreated infection or unexplained fever

Your physician will explain the procedure, along with its risks and benefits. In addition, you will also be instructed to do the following:

• Sign an informed consent
• What foods and liquids can be taken 24 hours before the test
• Fast for six to eight hours before the cath procedure
• Inform the doctor of any allergies to the dyes used in the cath procedure.
• Inform the doctor about any medical and medication history, especially any drug allergies.
• Stop taking specific medicines before the procedure.
• Ask someone to accompany you during the procedure.

• Before the cath procedure, a nurse will put an intravenous (IV) line into the vein of the arm to inject sedatives to make you relax.
• Your doctor will use a local anesthetic to numb the area, where the catheter goes in.
• The groin area is cleaned and shaved. The doctor will puncture your skin with a needle to gain access to the blood vessel.
• The doctor will insert an instrument known as an introducer sheath from which the catheter advances toward the blood vessels. You might feel some pressure. If you feel any pain, immediately inform the doctor.
• When the catheter reaches the arteries, it will inject a small amount of dye into the arteries.
• The X-ray camera will take pictures of your arteries and heart chambers. The catheter is removed gradually once the procedure ends.

You will be sent to the recovery room for a few hours. During this time:

• Pressure will be applied to the puncture site to stop bleeding
• You will have to lie straight on the bed. 
• Your vital signs such as blood pressure and pulse will be checked during your recovery
• Inform the doctor about any swelling, pain, or bleeding at the puncture site.

A heart cath is generally very safe. But as with any procedure, there are some risks with heart catheterization too.

Risks include:

• Heart attack
• Blood clots
• Infection
• Kidney damage
• Stroke
• Bruises
• Bleeding
• Arrhythmia
• Allergic reaction to the dye
• Air embolism (where air enter into the blood vessel)