What is supraventricular tachycardia?

Having supraventricular tachycardia (SVT) means that sometimes your heart beats abnormally fast. This fast rhythm is caused by connections that don't work right in the electrical system of the heart. You may feel a fluttering in your chest (palpitations) and have a fast pulse. When your heart is beating fast, you may feel lightheaded, be short of breath, or feel discomfort in the chest.

Treatments can stop SVT. Treatments that are done in a hospital include medicine, cardioversion, or a procedure called catheter ablation.

There are also some things you can do to help prevent and stop SVT when it happens. You may take medicine to help prevent an episode. Your doctor may also suggest you try vagal maneuvers to help slow your heart rate if you have an episode. Your doctor can show you how to do them.

Symptoms of SVT include:

• A racing or fluttering feeling in the chest (palpitations).
• Chest discomfort, such as pressure, tightness, or pain.
• Fainting, or feeling lightheaded or dizzy.
• Shortness of breath.
• A pounding pulse. You may feel or see your pulse beating, especially at your neck, where large blood vessels are close to the skin.
• Sweating.

Some people with SVT have no symptoms.

SVT does not always need to be treated. If needed, treatment options include medicine, cardioversion, and a procedure called catheter ablation. Your doctor may also teach you how to slow your heart rate on your own with physical actions called vagal maneuvers. You and your doctor can decide what treatment is right for you.

Your doctor may diagnose SVT based on a physical exam, your symptoms and history, and a test called an electrocardiogram (EKG, ECG). You may need other tests such as an electrophysiology study, blood tests, chest X-rays, or an echocardiogram to identify what type of SVT you have or find the cause.

• If you take medicine, take it exactly as prescribed. Call your doctor if you think you are having a problem with your medicine. You will get more details on the specific medicines your doctor prescribes.
• If your doctor showed you how to do vagal maneuvers, try them when you have an episode. These maneuvers include bearing down or putting an ice-cold, wet towel on your face.
• Monitor your condition by keeping a diary of your SVT episodes. Bring this to your doctor appointments.
  • Write down how fast or slow your heart was beating. To count your heart rate:
    • Gently place 2 fingers of your hand on the inside of your other wrist, below your thumb.
    • Count the beats for 30 seconds.
    • Then, double the result to get the number of beats per minute.
  • Write down if your heart rhythm was regular or irregular.
  • Write down the symptoms you had.
  • Write down the time of day your symptoms occurred.
  • Write down how long your symptoms lasted.
  • Write down what you were doing when your symptoms started.
  • Write down what may have helped your symptoms go away.
• If they trigger episodes, limit or avoid alcohol or drinks with caffeine.
• Do not use over-the-counter decongestants, herbal remedies, diet pills, or "pep" pills, which often contain stimulants.
• If you use stimulant drugs, quit or cut back as much as you can. These drugs include cocaine and methamphetamine. It's safest not to use them at all. Talk to your doctor if you need help decreasing your use.
• If you smoke, quit or cut back as much as you can. Smoking can make this condition worse. If you need help quitting, talk to your doctor about stop-smoking programs and medicines. These can increase your chances of quitting for good.
• Be alert for new or worse symptoms, such as shortness of breath, pounding of your heart, or unusual tiredness. If new symptoms develop or your symptoms become worse, call your doctor.

Most episodes of SVT are caused by faulty electrical connections in the heart. Some types of SVT may run in families, such as Wolff-Parkinson-White syndrome. SVT also can be caused by certain health problems, heart and lung medicines, or surgery.

Supraventricular tachycardia (SVT) means that from time to time your heart beats abnormally fast. For most people who have SVT, the heart still works normally to pump blood through the body. But SVT becomes a problem when it happens often, lasts a long time, or causes symptoms.