It must be very scary to have such a serious decision to make. I will do my best to give you the best information I can to ease your concern by helping you understand the process that is involved with catheter ablations. Working in ICU for years, I have cared for many patients with cardiac ablations and have rarely seen patients who have had complications as a result of the catheter ablation, and when they have, they've been extremely minor.
You are experiencing a tachycardia (any heart rate over 100 beats per minute) with a life-threatening rate of 190 - 220 beats per minute. You mentioned that you were once given medication to slow your rate and it did not work. Your options are limited if this cannot be controlled with medication. I don't believe you can afford NOT to have the procedure done.
The heart has an electrical pathway that "triggers" our hearts to beat. In your case, something is disrupting that pathway, causing you to have this very serious, life threatening heart rhythm. When you are in this extremely fast rhythm, your heart is not able to effectively pump enough blood out to the rest of your body. Without adequate blood supply, cells in the body can die. That is why it is so important to correct this problem.
Your concerns were the risks. Infection is always a risk with any invasive procedure, but catheter ablation is done under the same sterile procedures as in an operating room to greatly reduce the risk of infection. Usually the procedure is done in an EP lab. (Electrophysiology lab.) If the hospital is not equipped with an EP lab, it may be done in a cath lab. Bleeding is another risk because the physician is going to be inserting the catheter into a blood vessel. To minimize the risk of bleeding, firm pressure will be applied for several minutes after the catheter is removed and then a pressure dressing applied. You will be closely monitored for bleeding after the procedure along with continued heart monitoring.
During the procedure, you will have an IV so that medications can be given if necessary and so that you can be given sedation to help you relax. It may sound scary to be awake during the procedure, but it is actually beneficial for you to be able to communicate with the physician and staff if you have any questions, concerns, or request for more sedation, etc. You may experience some pressure at the insertion site of the catheter and possibly some mild chest discomfort, which is normal. Some people actually fall asleep during the procedure from the sedation, and that is okay, too. The physician will insert the catheter into a blood vessel either in your neck or in your groin. The decision on where to insert the catheter is usually based on the physician's preference and patient criteria. You can ask the physician before the procedure which site he/she plans to insert the catheter. The area will be prepped (sterilized and perhaps shaved if necessary.) There will be a special X-ray called a fluoroscopy. A fluoroscopic camera is a special X-ray that gives continuous pictures (a video X-ray.) The fluoroscopy is what the physician will use to guide the catheter to the site in your heart that is triggering the tachycardia. Once the area is identified, it will be ablated with the tip of the catheter causing a lesion that will ultimately turn into scar tissue so that area will not be able to trigger your tachycardia.
I believe that the ablation is the right choice for you. Please don't be afraid to ask your physician questions before the procedure including all the concerns you have. I realize you are in the service, but maybe plan to have a close friend or maybe a family member be present on the day of your procedure for moral support.
My best to you. Please come back here for any clarification or concerns.