SVT (Supraventricular Tachycardia)

What is SVT (supraventricular tachycardia)?

When your heart rhythm isn’t normal or the speed of the heartbeats isn’t right, you might have an arrhythmia. There are different names for different kinds of arrhythmias, depending on where they happen in the heart and what causes the problem. Tachycardia means your heart is beating too fast. It can reach more than 100 beats a minute while resting.

With SVT (supraventricular tachycardia), your fast heart rate begins in your upper heart chambers. The cause is a problem with the electrical signals and circuitry in the heart. When your heart is beating too fast, your heart can’t fill with blood between beats, making it hard to get enough blood to your body.

Think about it like this: If elevator doors close too quickly, people don’t have enough time to get into the elevator before the doors close. Similarly, when the heart beats too quickly, there’s not enough time to fill with blood before the heart chambers contract.

There are different types of SVT (supraventricular tachycardia). They are:

• Premature atrial contractions (PACs).
• Paroxysmal supraventricular tachycardia (PSVT).
• Accessory pathway tachycardias such as Wolff-Parkinson-White (WPW) syndrome.
• AV (atrioventricular) nodal re-entrant tachycardia (AVNRT).
• Atrial tachycardia.
• Atrial fibrillation.
• Atrial flutter.

Who does SVT (supraventricular tachycardia) affect?

Children and adults can get SVT (supraventricular tachycardia). Women get it more than men. Others are more likely to get this condition because they:

• Have anxiety.
• Drink more alcohol than recommended by your provider.
• Smoke or use tobacco products.
• Drink more than the recommended amount of coffee or other drinks with caffeine.

Young people who are exercising or training hard are more likely to get short-lived paroxysmal supraventricular tachycardia (PSVT). AV (atrioventricular) nodal reentrant tachycardia (AVNRT) is common in young adults and the elderly. Accessory pathway tachycardias (including WPW syndrome) are common in children younger than 12.

Older adults and people who are anxious or have too much caffeine are more likely to have premature atrial contractions (PACs). You’re more likely to get atrial flutter if you have lung disease, are an older adult or have diabetes. Lung disease, heart disease, caffeine and alcohol put you more at risk for atrial tachycardia. People with lung and heart diseases are also more likely to get atrial fibrillation.

How common is SVT (supraventricular tachycardia)?

For every 1,000 people, 2.25 have SVT (supraventricular tachycardia).

What causes SVT (supraventricular tachycardia)?

A problem with your heart’s electrical signals or circuitry causes SVT, but some people may not be aware of what brings on their symptoms. Others have a clear “trigger” like stress or exercise that starts their SVT. Things that can bring about symptoms include:

• Too many heartbeats.
• Stress.
• Caffeine.
• Alcohol.
• Cigarette smoke.

People who are pregnant or have thyroid, lung or heart disease can also get SVT.

What are the symptoms of SVT (supraventricular tachycardia)?

You might not have any symptoms, but many people have a fast heartbeat of more than 100 beats per minute while at rest as one of their major symptoms. This can go on anywhere from seconds to hours. Other symptoms may include:

• Having chest pain.
• Feeling tired.
• Having a fast heartbeat.
• Feeling lightheaded.
• Sweating.
• Feeling dizzy.
• Passing out.
• Having palpitations (fluttering in your chest).
• Feeling short of breath.

People with a serious case may become unconscious or have cardiac arrest.

How is SVT (supraventricular tachycardia) diagnosed?

Your healthcare provider will most likely do an electrocardiogram (EKG or ECG). If your provider needs to study your heart for a longer amount of time, they may ask you to wear a heart monitor that records the electrical activity in your heart.

How is SVT (supraventricular tachycardia) treated?

You may not need treatment. Some people may feel better after resting more, drinking less coffee or alcohol or after quitting smoking.

These treatments may be the first things to try:

• Have your healthcare provider apply pressure to specific areas of your face and neck.
• Do the Valsalva maneuver (act like you are blowing air out of your mouth but close off your nose and mouth as if you were trying to poop or lift a weight).
• Lie down.
• Put an ice cold towel on your face.
• Cough.

People who require therapy in the form of a catheter ablation to eliminate the areas responsible for the abnormal electricity can have cure rates close to 95% depending on the specific SVT.

What medications are used to treat SVT (supraventricular tachycardia)?

Several medicines can slow down your heart rate:

• Adenosine.
• Atropine.
• Beta blockers.
• Calcium channel blockers.
• Digitalis (digoxin).
• Potassium channel blockers.

If your healthcare provider prescribes medicines for you, be sure to follow the instructions for taking them. Also, keep going to your follow-up appointments.

Are there complications or side effects to treatment for SVT (supraventricular tachycardia)?

Any medicine may have side effects. A catheter ablation helps most people with SVT (supraventricular tachycardia) and has a low risk of major complications.

How can I reduce my risk of experiencing symptoms from SVT (supraventricular tachycardia)?

If your SVT (supraventricular tachycardia) is from causes you can change or modify, you can:

• Manage your stress.
• Drink less alcohol.
• Stop smoking.
• Drink less coffee and other things that have caffeine.
• Rest more.

You should also keep taking the medicine your healthcare provider prescribed for you.

What can I expect if I have SVT (supraventricular tachycardia)?

Some people with SVT (supraventricular tachycardia) may not need treatment at all. You may not have symptoms or your symptoms may range from mild to severe.

Lifestyle changes can help some people with their symptoms. Others need to take medicine to slow down their heart rate. In certain circumstances, catheter ablation is a definitive therapy and should be considered before trying medications. The cure rate is very high in people who have a catheter ablation.

How do I take care of myself if I have SVT (supraventricular tachycardia)?

Lifestyle changes can help with SVT (supraventricular tachycardia). You can:

• Manage your stress.
• Drink less alcohol.
• Stop smoking.
• Drink less coffee and other things that have caffeine.
• Rest more.

You should also keep taking the medicine your healthcare provider prescribed for you.

When should I see my healthcare provider for SVT (supraventricular tachycardia)?

You should see your doctor if you have symptoms of SVT (supraventricular tachycardia), including:

• Having chest pain.
• Feeling tired.
• Having a fast heartbeat.
• Feeling lightheaded.
• Feeling dizzy.
• Passing out.
• Having palpitations (fluttering in your chest).
• Feeling short of breath.

When should I go to the ER for SVT (supraventricular tachycardia)?

Call an ambulance if you:

• Have chest pain.
• Have trouble breathing.
• Feel really faint.

What questions should I ask my doctor about SVT (supraventricular tachycardia)?

• Do I have a mild or serious case?
• What is the best treatment for my situation?
• It can be helpful to keep track of any symptoms you’ve had and share them with your healthcare provider.

A note from Cleveland Clinic

SVT (supraventricular tachycardia) is a problem with your heartbeat’s speed or rhythm (arrhythmia). Depending on your situation, there may be simple things you can do yourself to help with symptoms. You may need medicine to slow down your heartbeat. Be sure to keep taking medicine prescribed to you and keep up with follow-up appointments. A catheter ablation has a high cure rate and low risk of complications. Ask your healthcare provider what’s best for you.