Normally, your heart has a strong, steady beat. That beat is controlled by the heart's electrical system. Sometimes that system does not work right, causing a heartbeat that is too fast. Supraventricular tachycardia (SVT) is one type of fast heart rate.

Catheter ablation is a way to get into your heart—without surgery—and fix the electrical problem. It's like working on the spark plugs in your car without having to open the hood.

• It's done in a hospital.
• The doctor inserts thin, flexible tubes called catheters into a vein, usually in the groin or neck. Then the doctor threads the catheters up into your heart.
• X-rays and other images of the heart help the doctor see where to move the catheters.
• The catheters use extreme heat or cold to destroy the areas in your heart that are causing the electrical problem.

It may seem like a bad idea to destroy parts of your heart on purpose. But the areas that are destroyed are very tiny and don't affect your heart's ability to do its job.

Catheter ablation might be done if you have symptoms that bother you a lot, you don't want to take heart rhythm medicine, or medicine has not worked for you.

This treatment does have some serious risks, but they are rare. Many people decide to have ablation because they hope to feel much better afterward. That hope is worth the risks to them. But the risks may not be worth it for people who have few symptoms.

Catheter ablation works well to stop supraventricular tachycardia (SVT) and the symptoms it causes. How well it works can depend on the type of SVT. These success rates cover the more common SVT types called AVNRT (atrioventricular nodal reentrant tachycardia) and AVRT (atrioventricular reciprocating tachycardia).

Catheter ablation stops SVT in about 93 to 97 people out of 100.^{footnote 2, footnote 3} This means that ablation might not work for 3 to 7 people out of 100.

Sometimes, the first ablation does not get rid of SVT completely. SVT might come back in 5 to 8 people out of 100.^{footnote 2, footnote 3} This means that the problem might not come back in 92 to 95 people out of 100. A second ablation usually gets rid of SVT.

Overall, problems might happen in about 3 people out of 100.^{footnote 2, footnote 3} This means that about 97 people out of 100 may not have problems. If problems happen during and soon after the procedure, your doctor is prepared to fix them right away.

Your risk of problems depends partly on the type of SVT that you have. Your doctor can help you understand your risk. The doctor can also help you decide whether the possible benefits of ablation outweigh these risks:

• Problems might happen because of the catheter that was inserted in a vein. They include minor pain, bleeding, and bruising.
• Pacemaker placement. If there is damage to the heart's electrical system during the procedure, you will need a pacemaker. This may happen in about 1 out of 100 people.^{footnote 1} This means that 99 out of 100 people may not need a pacemaker. With some types of SVT, where the abnormal cells are not close to the heart's electrical system, there is a smaller risk of needing a pacemaker.
• Serious problems. Serious problems include heart attack, stroke, or damage to the heart. They are more likely with certain types of SVT. Your doctor can help you know your risk. Serious problems happen to less than 1 out of every 100 people.^{footnote 2} This means that more than 99 out of every 100 people do not have serious problems. Serious problems that might happen also include dangerous blood clots in the lungs.
• Death. Less than 1 out of every 100 people die during or soon after this procedure.^{footnote 2, footnote 3} This means that more than 99 out of every 100 people don't die during or soon after the procedure.