You need not fear that you will feel any pain. You will have already received some sedation through the IV in your arm to keep you calm and comfortable. You will also see the operator inject some local anesthetic in to the groin area to numb it. Local anesthetics similar to novacaine are used for this purpose. If you still feel pain, let your doctor or the nurse standing near your head know immediately, so that additional anesthetic can be injected. It is normal to feel some pressure during this process as the operator presses on your groin while feeling for the femoral artery pulse. The operator will do the same thing on both sides of your groin. Once the groin area is fully numb, the operator will obtain access to the femoral vein using a short needle and insert a flexible guide wire into the blood vessel through the needle. This will be done twice on the right side of your groin. This portion of the procedure can be longer and more difficult in patients who are very obese and have a lot of abdominal and groin fat. Using the same technique, left femoral vein access on the left side is also obtained, and a short, thin sheath is placed over the guide wire. This will be used for placing the intracardiac echo catheter. You will see the operator placing two short, thin sheaths in the right femoral vein. These are later exchanged for longer transseptal sheaths. These sheaths are flushed with a saline solution containing a drug called heparin to prevent clot from forming. Then we place a long guide wire through the sheath, up into the heart, and then upwards through a vein called the superior vena cava, to enter the internal jugular vein. This guide wire is used as a landmark for obtaining access to the right internal jugular vein under x-ray guidance. The neck is draped, local anesthetic is used to numb the neck, and access to the internal jugular vein is obtained using a short needle, just like at the groin. A thin, flexible guide wire is inserted, and a short, thin sheath is placed over the wire. This neck venous access is obtained so that a long, thin catheter with multiple electrodes can be placed into the upper chambers of the heart. This catheter is designed to read the electrical activity of the heart from both the right and left upper chambers. The catheter goes from the neck into the right atrium and then on into a vein in the heart called the coronary sinus, to read the electrical activity of the heart during the procedure.