The heart with a catheter inserted to inject alcohol into a thickened area of the septum.

Alcohol septal ablation is a procedure to treat a heart condition that causes the wall of the heart to thicken (hypertrophic cardiomyopathy). This is usually a genetic condition that a person is born with. If you have hypertrophic cardiomyopathy, the wall (septum) that separates one side of your heart from the other becomes thick. This makes it hard for your heart to pump blood. This, in turn, causes symptoms such as light-headedness, chest pain, and shortness of breath.

Alcohol septal ablation may reduce the thickening of your septum. This helps your heart to pump blood more easily and may relieve your symptoms. Alcohol septal ablation is not open-heart surgery. In this procedure, a long, thin tube (catheter) is used to inject alcohol into the thickened part of the septum. You may need this procedure if other treatments, including medicines, have not worked.

Tell a health care provider about:

  • Any allergies you have.

  • All medicines you are taking, including vitamins, herbs, eye drops, creams, and over-the-counter medicines.

  • Any problems you or family members have had with anesthetic medicines.

  • Any bleeding problems you have.

  • Any surgeries you have had.

  • Any medical conditions you have.

  • Whether you are pregnant or may be pregnant.

What are the risks?

Generally, this is a safe procedure. However, problems may occur, including:

  • Abnormal heart rhythm during or after the procedure.

  • Blocked heart rhythm signals (heart block). This may require a pacemaker.

  • Heart attack.

  • Bleeding.

  • Infection.

  • Allergic reactions to medicines or dyes.

  • Damage to nearby structures or organs.

  • Tearing of heart muscle.

Risks also include:

  • Buildup of fluid or blood around the heart.

  • Kidney failure.

  • Blood clots.

What happens before the procedure?

When to stop eating and drinking

Follow instructions from your health care provider about what you may eat and drink before your procedure. These may include:

  • 8 hours before your procedure

    • Stop eating most foods. Do not eat meat, fried foods, or fatty foods.

    • Eat only light foods, such as toast or crackers.

    • All liquids are okay except energy drinks and alcohol.

  • 6 hours before your procedure

    • Stop eating.

    • Drink only clear liquids, such as water, clear fruit juice, black coffee, plain tea, and sports drinks.

    • Do not drink energy drinks or alcohol.

  • 2 hours before the procedure

    • Stop drinking all liquids.

    • You may be allowed to take medicines with small sips of water.

If you do not follow your health care provider’s instructions, your procedure may be delayed or canceled.


Ask your health care provider about:

  • Changing or stopping your regular medicines. This is especially important if you are taking diabetes medicines or blood thinners.

  • Taking over-the-counter medicines, vitamins, herbs, and supplements.

General instructions

  • You will have tests. These may include blood tests, an electrocardiogram (ECG), and imaging studies of your heart.

  • Do not use any products that contain nicotine or tobacco for at least 4 weeks before the procedure. These products include cigarettes, chewing tobacco, and vaping devices, such as e-cigarettes. If you need help quitting, ask your health care provider.

  • Plan to have a responsible adult take you home from the hospital or clinic.

  • Plan to have a responsible adult care for you for the time you are told after you leave the hospital or clinic. This is important.

What happens during the procedure?

  • An IV will be inserted into one of your veins.

  • You will be given the following:

    • A medicine to help you relax (sedative).

    • A medicine to numb your groin or wrist area (local anesthetic).

  • A small incision will be made through the skin of your groin or wrist area.

  • You may be given IV medicines to thin your blood. This will reduce your risk of a blood clot.

  • An ablation catheter with a balloon on the end will be inserted into the groin or wrist artery and guided up to your heart.

  • Imaging studies will be done as the catheter enters your heart. These are done to see the position of the catheter inside the artery that leads to the septum. Dye may be injected through the catheter to get better images of your heart.

  • A second catheter (pacemaker catheter) may be placed through your groin or through a vein in your neck, then guided to your heart. This catheter can be used to control your heart rhythm if you have an abnormal heart rhythm or a blocked heart rhythm during or after the procedure.

  • When the ablation catheter is in the right position, alcohol will be injected into the thickened area of the septum. This will reduce the blood supply to your septum and cause some of the muscle cells to die. The thick muscle will be replaced with thin scar tissue. Imaging studies may be repeated.

  • When the procedure is done, the ablation catheter will be removed through your groin or wrist incision.

  • In some cases, the pacemaker catheter may need to be left in place.

  • The groin or wrist incision may be closed with a small internal stitch (suture), closure device, skin glue, or adhesive strips. It may be covered with a bandage (dressing). If you still have a pacemaker catheter, the incision will be closed and bandaged later after that catheter has been removed.

The procedure may vary among health care providers and hospitals.

What happens after the procedure?

  • You will need to lie flat for several hours. Your heart will need to be monitored in the hospital overnight.

  • When your heart rhythm is stable, your IV will be removed. If you have a pacemaker catheter, it may also be removed.

  • You will be able to eat a regular diet.

  • You may be encouraged to get out of bed to walk before discharge.

  • Imaging studies of your heart may be repeated.


  • Alcohol septal ablation is a procedure to treat a condition that causes the wall of the heart to thicken (hypertrophic cardiomyopathy).

  • You may need this procedure if medicines and other treatments have not relieved your symptoms.

  • In this procedure, alcohol is injected through a long, thin tube (ablation catheter) that leads from a groin or wrist artery to your heart. The alcohol causes some of the muscle cells to die. This causes the thick muscle to be replaced with thinner scar tissue.

  • You may also need a pacemaker to control your heart rhythm during the procedure.

This information is not intended to replace advice given to you by your health care provider. Make sure you discuss any questions you have with your health care provider.