Supraventricular tachycardia (SVT) – NHS

Supraventricular tachycardia (SVT) is a condition where your heart suddenly beats much faster than normal. It’s not usually serious, but some people may need treatment.

Causes of supraventricular tachycardia (SVT)

SVT happens when the electrical system that controls your heart rhythm is not working properly.

This causes your heart to suddenly beat much faster. It can then slow down abruptly.

A normal resting heart rate is 60 to 100 beats per minute (bpm). But with SVT your heart rate suddenly goes above 100bpm. This can happen when you’re resting or doing exercise.

Symptoms of supraventricular tachycardia (SVT)

Having SVT means your heart suddenly beats faster.

This:

• usually lasts for a few minutes, but can sometimes last for several hours
• can happen several times a day or once a year – it varies
• can be triggered by tiredness, caffeine, alcohol or drugs – but often there’s no obvious trigger
• can happen at any age, but often starts for the first time in children and young adults – many people have their first symptoms between 25 and 40

You may get no other symptoms, but sometimes people also:

• have chest pain
• feel weak, breathless or lightheaded
• feel tired
• feel sick or are sick

Non-urgent advice: See a GP if you keep getting a fast heartbeat

It’s important to get it checked out. You might need a test, such as an electrocardiogram (ECG), to find out what’s going on.

Immediate action required: Call 999 or go to A&E if:

• you have been diagnosed with SVT and your episode has lasted longer than 30 minutes
• you have sudden shortness of breath with chest pain

You need to go to hospital for treatment immediately.

Things you can do to help with supraventricular tachycardia (SVT)

If your episodes of SVT only last a few minutes and do not bother you, you may not need treatment.

You can make changes to your lifestyle to reduce your chances of having episodes, such as:

• cutting down on the amount of caffeine or alcohol you drink
• stopping or cutting back on smoking
• making sure you get enough rest

Your doctor may also be able to recommend some simple techniques to help stop episodes when they happen.

Treating supraventricular tachycardia (SVT) in hospital

SVT is rarely life threatening. But you may need treatment in hospital if you keep having long episodes.

This may include:

• medicines to control the episodes of SVT – given as tablets or through a vein
• cardioversion – a small electric shock to the heart to help it get back to a normal rhythm
• catheter ablation – a treatment where thin tubes are placed through a vein or artery into your heart to correct the problem with the electrical system; this permanently cures the problem in most patients

Find out more about:

• cardioversion: British Heart Foundation
• catheter ablation: British Heart Foundation

Page last reviewed: 27 April 2021
Next review due: 27 April 2024

Supraventricular Tachycardia | Cedars-Sinai

ABOUT

CAUSES
DIAGNOSIS

TREATMENT

NEXT STEPS

What is supraventricular tachycardia?

Supraventricular tachycardias (SVT)
is a kind of abnormally fast heart rhythm (heartbeat). It’s a problem in the electrical
system of the heart. The word supraventricular means above the ventricles. With SVT,
the
abnormal rhythm starts in the upper heart chambers (atria). This condition is also
called paroxysmal supraventricular tachycardia. That’s because the fast heart rhythms
may start and stop abruptly. They can also occur with intervals of normal heart rhythm.

Normally, a special group of cells
begin the electrical signal that triggers your heartbeat. These cells are in the
sinoatrial (SA) node. In an adult, the sinus node sends out a regular electrical pulse
60 to 100 times per minute at rest. This node is in the right atrium, the upper right
chamber of your heart. The signal quickly travels down your heart’s conducting system
to
the ventricles, the 2 lower chambers of your heart. Along the way, the signal moves
through the atrioventricular (AV) node, a special group of cells between your atria
and
your ventricles. From there, the signal travels to your left and right ventricle.
As it
travels, the signal triggers nearby parts of your heart to contract. This helps your
heart pump in a coordinated way.

In SVT, the signal to start your
heartbeat doesn’t come from the SA node. Instead, it comes from another part of the
left or right atrium, or from the AV node. An area outside the SA node begins to fire
quickly, causing a rapid heartbeat of over 100 beats per minute. This shortens the
time
your ventricles have to fill. If your heartbeat is fast enough, your heart may not
be
able to pump enough blood forward to the rest of your body. The abnormal heart rhythm
may last for a few seconds to a few hours before your heart returns to its normal
rhythm.

There are several types of SVT:

• Atrioventricular nodal
  reentrant tachycardia (AVNRT).
  This is the most common type in adults. It
  occurs when you have 2 channels or pathways through the AV node, instead of just 1.
  The electricity can get into a looping circuit with signals going down one channel
  and up the other. It can occur at any age. But it most often starts in young
  adulthood. It’s slightly more common in women.
• Atrioventricular reciprocating
  tachycardia (AVRT).
  This is another common type of SVT. In this type, you are
  born with an extra electrical connection between the atrium and the ventricle (known
  as an accessory pathway) that can conduct electricity. This type lets your heart get
  caught up in a looping electrical circuit. The electricity either goes down the AV
  node and returns back to the atrium through the accessory pathway. Or the reverse
  occurs with the signal traveling down the accessory pathway and returning through
  the
  AV node. This circuit continues until it’s interrupted and the tachycardia stops.
  This type of SVT is slightly more common in younger women and children. It’s also
  called Wolff-Parkinson-White (WPW) syndrome.
• Atrial tachycardia. In this
  common type of SVT, a small group of cells in the atria start to fire abnormally,
  triggering the fast heartbeat. Multifocal atrial tachycardia is a related type. In
  this case, many groups of cells in your atria fire abnormally. These types of SVT
  happen more often in middle-aged people. Multifocal atrial tachycardia is more common
  in people with heart failure or other heart or lung diseases.

In general, SVT is somewhat uncommon. But it’s not rare. Atrial
fibrillation and atrial flutter are also technically types of SVT. But these are often
separated into their own category because they are linked with other risks. They can
also last for days or even years and have a different mechanism.

What causes supraventricular tachycardia?

SVT is often caused by faulty
electrical signaling in your heart. It’s often brought on by premature beats. Some
types
of SVT run in families, so genes may play a role. Other types may be caused by lung
problems. It can also be linked to some lifestyle habits or health problems. Some
of
these include:

• Too much caffeine or alcohol
• Heavy smoking
• Certain medicines
• Heart attack
• Mitral valve disease

What are the symptoms of supraventricular tachycardia?

You may not have any symptoms if
you have SVT. Symptoms may vary based on how long the tachycardia lasts and how fast
the
heart rate is. Common symptoms include:

• Chest discomfort
• Shortness of breath
• Fatigue
• Lightheadedness or dizziness
• Pulsations in the neck
• Unpleasant awareness of the heartbeat
  (palpitations)

Fainting, more severe chest pain, and nausea are less common
symptoms. In rare cases, SVT can cause sudden death.

How is supraventricular tachycardia diagnosed?

Diagnosis starts with a health
history and physical exam. Your healthcare provider will also use tests to help diagnose
SVT. These tests will help your provider identify the type of SVT you have. They also
help your provider check for possible underlying causes and complications. Tests might
include:

• Electrocardiogram (ECG), the most
  important first test to check the abnormal rhythm
• Continuous electrocardiogram to watch
  your heart rhythm over a longer period
• Blood work to test for various
  causes
• Chest X-ray to check for lung problems
  and look at the size of your heart
• Exercise stress test to see how your
  heart works during exercise
• Echocardiography to check your heart
  structure and function
• Electrophysiologic study (EPS) to
  evaluate the electrical activity and pathways in your heart

Your primary healthcare provider might first diagnose your SVT. But
they’ll likely send you to a healthcare provider who specializes in the heart
(cardiologist).

How is supraventricular tachycardia treated?

SVT needs short-term and long-term
treatment. Options for short-term treatment include:

• Maneuvers to stop SVT, such as bearing
  down
• Medicines to stop SVT, like calcium
  channel blockers, beta blockers, or adenosine
• Electrocardioversion, which sends a
  shock to the heart to get it back to a normal rhythm
• Catheter ablation

Maneuvers are often the first
treatment unless you have severe symptoms. These attempt to activate a nerve called
the
vagus nerve. Activating this nerve can cause a brief slowing of your heartbeat to
break
the abnormal circuit. Your healthcare provider might have you do a Valsalva maneuver
(you bear down with your stomach muscles, as though you were trying to have a bowel
movement). Your provider might also try massaging the carotid artery in your neck,
having you blow in a straw, or coughing hard. Each of these techniques can sometimes
bring you out of SVT. If they don’t, your provider might give you medicines. If your
symptoms are severe or your condition is unstable, you will often have
electrocardioversion as the first treatment.

Long-term treatment depends on the
type of SVT and the intensity of symptoms. You may not need any treatment for SVT
if you
have had only 1 episode or the episodes are very rare, especially if SVT went away
with
maneuvers alone. In some cases, your healthcare provider may prescribe medicines to
stop
SVT that you will need to take only as needed. Beta-blockers or calcium channel blockers
are common choices. This may be an option for you if you have fewer than 3 episodes
of
SVT per year. But the medicines may often take 15 to 30 minutes to take effect. If
your
SVT is more frequent, you may need to take medicine every day. Some people may need
to
take several medicines to prevent episodes of SVT.

Catheter ablation is the preferred
treatment for recurring SVT. In some cases, it may be the first advised treatment.
Ablation can often cure SVT. The procedure involves placing a small catheter through
a
blood vessel in the groin and threading it to your heart. Your healthcare provider
then
does a small burn or small freeze on the part of your heart that is causing the fast
heart rhythm. Ask your healthcare provider about what treatment option is right for
you.

How is supraventricular tachycardia managed?

Your healthcare provider might make
other recommendations to manage your SVT. These might include:

• Cutting back on alcohol and
  caffeine
• Not smoking
• Reducing stress
• Eating a heart-healthy diet

When should I call my healthcare provider?

Call your healthcare provider if
you have severe symptoms like palpitations, lightheadedness, chest pain, or sudden
shortness of breath. If your symptoms are increasing in severity or frequency, plan
to
see your healthcare provider as soon as possible.

Key points about supraventricular tachycardia

• SVT is a type of abnormal heart rhythm. Something signals a part
  outside of the SA node to fire much faster than it should or something triggers the
  signal to follow a looping circuit. This results in a fast heartbeat that can last
  anywhere from a few seconds to several hours.
• There are several subtypes of SVT.
  Your treatment options may vary based on what subtype you have.
• In rare cases, SVT can cause sudden
  death.
• You might need a shock to the heart if
  you are having severe symptoms from SVT.
• Some people with SVT need to take
  medicines only when an episode of SVT happens. Others need to take medicine all the
  time. Ablation is often a good option for many people.
• It is important to follow your
  healthcare provider’s instructions about medicine and lifestyle management.

Next steps

Tips to help you get the most from
a visit to your healthcare provider:

• Know the reason for your visit and
  what you want to happen.
• Before your visit, write down
  questions you want answered.
• Bring someone with you to help you ask
  questions and remember what your provider tells you.
• At the visit, write down the name of a
  new diagnosis and any new medicines, treatments, or tests. Also write down any new
  instructions your provider gives you.
• Know why a new medicine or treatment
  is prescribed and how it will help you. Also know what the side effects are.
• Ask if your condition can be treated
  in other ways.
• Know why a test or procedure is a and
  what the results could mean.
• Know what to expect if you do not take
  the medicine or have the test or procedure.
• If you have a follow-up appointment,
  write down the date, time, and purpose for that visit.
• Know how you can contact your provider
  if you have questions.

Medical Reviewer: Steven Kang MD

Medical Reviewer: Anne Clayton APRN

Medical Reviewer: Stacey Wojcik MBA BSN RN

© 2000-2022 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional’s instructions.

Supraventricular tachycardia (SVT) | First Clinical Medical Center

Supraventricular tachycardia (SVT) is a condition in which the heart suddenly begins to beat much faster than normal. It is usually not serious, but some people may need treatment.

Causes of supraventricular tachycardia (SVT)

SVT occurs when the electrical system that controls the heart’s rhythm is not working properly.

This causes the heart to suddenly start beating much faster. Then it can slow down dramatically.

The normal resting heart rate is 60-100 beats per minute (bpm). But in SVT, the heart rate suddenly rises above 100 beats per minute. This can happen when you are resting or exercising.

Supraventricular tachycardia (SVT) symptoms

Supraventricular tachycardia means that your heart suddenly starts beating faster.

This:

• usually lasts a few minutes but can sometimes last several hours
• may occur several times a day or once a year – it depends on the situation
• may be triggered by fatigue, caffeine, alcohol or drugs – but often no obvious cause
• can occur at any age, but often first begins in children and young adults—many people have their first symptoms between the ages of 25 and 40.

You may not have any other symptoms, but sometimes people with this condition also:

• experiencing chest pain
• feel weak, short of breath or dizzy
• feeling tired
• feeling unwell or sick

Important tip: see your doctor if you have a fast heartbeat.

It is important to get tested. You may need a test, such as an electrocardiogram (ECG), to find out what’s going on.

Call an ambulance immediately if:

• you are diagnosed with SVT and the attack lasts more than 30 minutes
• you have sudden shortness of breath with chest pain

You need to go to the hospital immediately for treatment.

What you can do to help with supraventricular tachycardia (SVT)

If your SVT attacks last only a few minutes and don’t bother you, you may not need treatment.

Disease Prevention

You can make lifestyle changes to reduce the chance of seizures, such as:

• reduce the amount of caffeine or alcohol you drink
• stop or reduce smoking
• make sure you get enough rest.

Your doctor can also give you some simple methods to help stop seizures when they happen.

Treatment of supraventricular tachycardia (SVT) in hospital

Supraventricular tachycardia is rarely life threatening. But you may need treatment in the hospital if you continue to have prolonged seizures.

This may include:

• medicines to treat SVT attacks – pills or by vein
• cardioversion – a small electric shock to the heart to help it return to a normal rhythm
• catheter ablation, a procedure in which thin tubes are inserted through a vein or artery into the heart to correct an electrical problem; in most patients, this solves the problem permanently.

Supraventricular tachycardia – Medical Center “Lіko-Med”

What is it?

Supraventricular tachycardia (SVT) is a type of accelerated heart rate that develops in its upper sections (atria). Another name for SVT is paroxysmal supraventricular tachycardia. “Paroxysmal” means “periodic”: it comes on suddenly and ends after a few minutes or hours.

SVT is characterized by a range of symptoms: anxiety, weakness, palpitations, dizziness.

SVT can be caused by drugs, heredity (Wolf-Parkinson-White syndrome), smoking, alcohol, drugs, and even stress. Supraventricular tachycardia is usually not life-threatening. However, frequent manifestations of the disease can weaken or even cause damage to the myocardium over time.

What to expect

SVT comes on suddenly and lasts for minutes or hours. In the case of a chronic course, the attack may not end for a long time, so it is stopped with the help of electrical impulse therapy or medication. In most cases, SVT goes away on its own. During an attack, you can self-administer a series of actions called “vagal maneuvers” (vagus nerve stimulation) to slow your heart rate.

Prevalence

The average incidence of SVT is 3 people per thousand population.

Treatment

The following are commonly used to treat supraventricular tachycardia:

drugs to restore the rhythm, such as calcium channel blockers and others,

electrical impulse therapy,

pacemakers to maintain a normal rhythm,

surgery.

What you can do yourself

In many cases, SVT does not require treatment and resolves on its own. Sometimes you can try to stimulate the vagus nerve (“vagal maneuver”), which includes the following actions:

hold your breath,

immerse your face in cold water,

cough,

tense and relax the abdominal muscles, as if emptying intestines,

· lie down and breathe deeply until the rhythm is restored.

What makes it worse

Some medications, hyperthyroidism (increased thyroid function), large amounts of caffeine and alcohol, and magnesium deficiency can aggravate the course of the disease.

When to see a doctor

Call your doctor if:

you have never had an arrhythmia and it lasts longer than a few minutes

you have had seizures before, but this time the usual methods do not help,

you feel dizzy or faint,

you have chest pains,

you are short of breath.

Do not go to the hospital on your own, call an ambulance.

What to ask your doctor

1. Will SVT happen all the time or is it a single episode?

2.