Supraventricular Tachycardia (SVT)

What is supraventricular tachycardia?

Supraventricular tachycardia (SVT) is a fast heart rate that starts in your upper heart chambers. When your heart is beating too fast at rest, it makes it hard to send enough blood to your body. Episodes can go on for seconds to hours.

When your heart beats too quickly, there’s not enough time for your heart chambers to fill with blood before they contract.

If you have symptoms, you may think something doesn’t feel right in your chest. Although it may be difficult, noting the details of what you’re experiencing can help a healthcare provider make a diagnosis.

Types of SVT

Different kinds of SVT include:

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

What does supraventricular tachycardia feel like?

You might not have any symptoms with SVT. But whether you realize it or not, your heart’s beating more than 100 times per minute while at rest.

Other supraventricular tachycardia symptoms may include:

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

Symptoms may range from mild to severe.

What causes SVT?

A problem with your heart’s electrical signals or circuitry causes SVT. Some people may not be aware of what brings their symptoms on. Others have a clear “trigger” that starts their SVT. Supraventricular tachycardia causes that can bring about symptoms include:

• Stress.
• Caffeine.
• Alcohol-containing beverages.
• Cigarette smoke.
• Physical activity.
• A shortage of sleep.
• Dehydration.

What are the risk factors?

Children and adults can get supraventricular tachycardia. Risk factors for SVT include:

• Being assigned female at birth (AFAB).
• Having anxiety.
• Drinking more alcohol-containing beverages than the suggested limit.
• Using tobacco products.
• Drinking more caffeine-containing beverages than the suggested limit.
• Doing hard physical training.
• Having lung disease, heart issues, thyroid disease or diabetes.
• Being pregnant.

What are the complications of supraventricular tachycardia?

A serious case of SVT may lead to:

• Heart failure.
• Unconsciousness.
• Cardiac arrest.

Is it life-threatening?

SVT isn’t life-threatening in most cases, but it can be for people with other heart issues.

How is supraventricular tachycardia diagnosed?

During a physical exam, your healthcare provider will ask about your medical history and the symptoms you’ve been having.

They’ll 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 supraventricular tachycardia treated?

You may not need SVT treatment. Some people may feel better after resting more, drinking less coffee or alcohol-containing drinks, or after quitting smoking. If those don’t help, you have lots of other options.

At-home treatments

Try one of these first:

• Lie down.
• Put an ice-cold towel on your face.
• Cough.

Medications for SVT

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.

Procedures and maneuvers

Your provider can use these methods for supraventricular tachycardia treatment:

• Vagal maneuvers like applying pressure to specific areas of your neck (carotid sinus massage).
• Cardioversion, which uses a shock to return your heart to a normal rhythm.
• Catheter ablation, which can eliminate the areas causing the abnormal electricity. In certain circumstances, your provider may consider catheter ablation before trying medications. Catheter ablation has a cure rate that can surpass 95% depending on the specific SVT type.
• Implantable cardioverter defibrillator (ICD), a device that can deliver a shock when you need it.

What are complications/side effects of treatment?

Any medicine may have side effects. Although a catheter ablation has a low risk of major complications, it may cause:

• Bleeding.
• Heart attack.
• Heart block.
• Stroke.

How soon after SVT treatment will I feel better?

Vagal maneuvers and at-home treatments can bring relief right away — if they work. Medicines and procedures are more reliable but take longer to work. If you’re having an SVT episode, it’s worth trying at-home treatments. For the long term, you may need medicines or procedures.

How can I lower my risk of supraventricular tachycardia?

If SVT is from causes you can change, you can:

• Manage your stress.
• Drink fewer alcohol-containing drinks.
• Stop using tobacco products.
• 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?

The outlook is good for most people with SVT. But if you have a structural issue with your heart, your prognosis (outlook) may not be as good. It depends on the severity of the problem.

Can you live a normal life with supraventricular tachycardia?

Yes. You can manage very infrequent episodes with medications. With successful treatments like catheter ablation, you can do many of the typical things you want to. Ablation can cure certain forms of SVT.

How do I take care of myself?

Changes you make in your daily routines can help with SVT (supraventricular tachycardia). You can:

• Manage stress.
• Drink fewer alcohol-containing beverages.
• Stop smoking.
• Drink less coffee and other caffeinated drinks.
• Get more rest.

You should also continue taking your prescription medications.

When should I see my healthcare provider?

You should see your provider 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?

Call 911 or your local emergency services number if you:

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

What questions should I ask my provider?

Questions to ask your provider may include:

• How dangerous is the type of SVT I have?
• Do I have a serious case that needs treatment?
• Do I need medication or a procedure?