Supraventricular Tachycardia

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Supraventricular Tachycardia

Topic Overview

Illustration of the heart

Is this topic for you?

Atrial fibrillation and ventricular tachycardia are types of fast heart rates that can be serious. If you have one of these heart problems, see the topic Atrial Fibrillation or Ventricular Tachycardia.

What is supraventricular tachycardia?

Supraventricular tachycardia (SVT) means that from time to time your heart beats very fast for a reason other than exercise, high fever, or stress. Types of SVT include:

During an episode of SVT, the heart’s electrical system doesn't work right, causing the heart to beat very fast. The heart beats at least 100 beats per minute and may reach 300 beats per minute. After treatment or on its own, the heart usually returns to a normal rate of 60 to 100 beats a minute.

SVT may start and end quickly, and you may not have symptoms. SVT becomes a problem when it happens often, lasts a long time, or causes symptoms.

SVT also is called paroxysmal supraventricular tachycardia (PSVT) or paroxysmal atrial tachycardia (PAT).

What causes SVT?

Most episodes of SVT are caused by faulty electrical connections in the heart. What causes the electrical problem is not clear.

SVT also can be caused by certain medicines. Examples include very high levels of the heart medicine digoxin or the lung medicine theophylline.

Some types of SVT may run in families, such as Wolff-Parkinson-White syndrome. Or they may be caused by a lung problem such as COPD or pneumonia.

What are the symptoms?

Some people with SVT have no symptoms. Others may have:

  • Palpitations, a feeling that the heart is racing or pounding.
  • A pounding pulse.
  • A dizzy feeling or may feel light-headed.

Other symptoms include near-fainting or fainting (syncope), shortness of breath, chest pain, throat tightness, and sweating.

How is SVT diagnosed?

Your doctor will diagnose SVT by asking you questions about your health and symptoms, doing a physical examination, and perhaps giving you tests. Your doctor:

  • Will ask if anything triggers the fast heart rate, how long it lasts, if it starts and stops suddenly, and if the beats are regular or irregular.
  • May do a test called an electrocardiogram (EKG, ECG). This test measures the heart's electrical activity and can record SVT episodes.

If you do not have an episode of SVT while you're at the doctor's office, your doctor probably will ask you to wear a portable electrocardiogram (EKG), also called an ambulatory electrocardiogram. When you have an episode, the device will record it.

Your doctor also may do tests to find the cause of the SVT. These may include blood tests, a chest X-ray, and an echocardiogram, which makes a picture of the heart.

How is it treated?

Some SVTs don't cause symptoms, and you may not need treatment. If you do have symptoms, your doctor probably will recommend treatment.

To treat sudden episodes of SVT, your doctor may:

  • Prescribe a medicine to take when the SVT occurs.
  • Show you how you can slow your heart rate on your own. You may be able to do this by coughing, gagging, or putting your face in ice-cold water. These are called vagal manoeuvres.

If these treatments don't work, you may have to go to your doctor's office or the emergency room. You may get a fast-acting medicine such as adenosine or verapamil. If the SVT is serious, you may have electrical cardioversion, which uses an electrical current to reset the heart rhythm.

If you often have episodes of SVT, you may need to:

  • Take medicine every day to prevent the episodes or slow your heart rate.
  • Try catheter ablation. This procedure destroys a tiny part of the heart that causes the problem.

What can you do at home to prevent SVT?

You can try some things at home to help prevent SVT by avoiding the things that trigger it.

  • Limit alcohol to 2 drinks a day if you are a man and 1 drink a day if you are a woman.
  • Limit caffeine. Even decaffeinated teas or coffee can cause SVT in some people.
  • Don't smoke.
  • Avoid over-the-counter decongestants, herbal remedies, diet pills, and "pep" pills.
  • Don't use illegal drugs, such as cocaine, ecstasy, or methamphetamine.

To find your triggers, keep a diary of your heart rate and your symptoms. You might find, for example, that smoking or caffeine causes your SVT episodes.

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  Heart Problems: Should I Have Catheter Ablation?

Cause

Two common types of supraventricular tachycardia—atrioventricular reciprocating tachycardia (AVRT) and atrioventricular nodal re-entrant tachycardia (AVNRT)—are caused by an abnormal electrical pathway in the heart and often occur in people who do not have any other type of heart disease. What causes this abnormal pathway is not clear.

Some experts believe that AVRT—specifically Wolff-Parkinson-White syndrome—may in some cases be inherited.

For more information about how SVT happens, see the topic Types of Supraventricular Tachycardia.

Other types of supraventricular tachycardia may be caused by:

Symptoms

Symptoms of supraventricular tachycardia include:

  • A racing or fluttering feeling in the chest (palpitations).
  • Chest discomfort (pressure, tightness, pain).
  • Light-headedness or dizziness.
  • Fainting (syncope).
  • 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.
  • Tightness or fullness in the throat.
  • Tiredness (fatigue).
  • Excessive urine production.

What Increases Your Risk

Some lifestyle factors can raise your risk of having an episode of supraventricular tachycardia, such as overuse of caffeine, nicotine, or alcohol or use of illegal drugs, such as stimulants like cocaine or methamphetamine.

Decongestants that contain stimulants should also be avoided, including oxymetazoline (such as Dristan and other brands) and pseudoephedrine (such as Sudafed and other brands). Doctors also warn against using non-prescription diet pills or "pep" pills, because many contain caffeine, ephedra, ephedrine, the herb ma huang, or other stimulants.

Conditions that affect the lungs, such as chronic obstructive pulmonary disease (COPD), pneumonia, heart failure, and pulmonary embolism, can raise your risk for multifocal atrial tachycardia (MAT), a type of supraventricular tachycardia.

Many experts believe that Wolff-Parkinson-White syndrome may in some cases be inherited. If you have a first degree relative, which is a parent, brother, or sister, with this disorder and he or she has symptoms, talk with your doctor about your risk of developing this abnormal heart rhythm.

When to Call a Doctor

Call 911 or seek emergency services immediately if you have a fast heart rate and you:

  • Faint or feel as though you are going to faint.
  • Have severe shortness of breath.
  • Have chest pain.
  • Have symptoms of a heart attack or stroke.

Call your doctor if you are having fluttering in your chest (palpitations) that persists and does not go away quickly or if you have frequent palpitations.

If you have a pacemaker

Call your doctor right away if you have symptoms that could mean your device is not working properly, such as:

  • Your heartbeat is very fast or slow, skipping, or fluttering.
  • You feel dizzy, light-headed, or faint.
  • You have shortness of breath that is new or getting worse.

Watchful Waiting

If you have a fast heart rate and you have symptoms that may be caused by the fast heart rate, watchful waiting is not appropriate. See your doctor.

Who to See

Your family doctor or general practitioner can check symptoms of a fast or irregular heartbeat. You may be referred to a specialist, such as:

Most people with supraventricular tachycardia need to see a cardiologist or electrophysiologist for follow-up care.

Examinations and Tests

An exact diagnosis is important because the treatment you receive depends on the type of tachycardia you have. Supraventricular tachycardia can sometimes be diagnosed simply on the basis of a medical history and physical examination and a few simple tests. Tests that may be done to monitor your heart and diagnose the type of fast heart rate that you have include:

  • Electrocardiogram (EKG, ECG), which measures the electrical impulses in the heart. If an electrocardiogram is performed while the fast heart rate is occurring, it often provides the most useful information.
  • Ambulatory electrocardiogram. A portable EKG, such as a Holter monitor, can record your heart rhythm on a continuous basis, usually over a 24-hour period. If your symptoms are infrequent, your doctor may use another type of ambulatory electrocardiogram called a cardiac event monitor. When you have symptoms, you activate the monitor, which records your heart rhythm.
  • Electrophysiology study. In this test, flexible wires are inserted into a vein, usually in the groin, and threaded into the heart. Electrodes at the end of the wires transmit information about the heart's electrical activity. Your doctor uses this information to see whether there is an extra electrical pathway inside the heart and, if so, where it is located. Catheter ablation can be done during this test to treat abnormal pathways and correct the supraventricular tachycardia.
  • Medicine trial. Giving certain medicines while you are experiencing a fast heart rate, and monitoring what happens, may sometimes help your doctor find out what type of fast heart rate problem you have.

After finding tachycardia, your doctor may need to search for its cause. The specific tests needed depend on the particular tachycardia. These tests may include:

Treatment Overview

Supraventricular tachycardia is usually treated if:

  • You have symptoms such as dizziness, chest pain, or fainting (syncope) that are caused by your fast heart rate.
  • Your episodes of fast heart rate are occurring more frequently or do not revert to normal on their own.

Treatment for sudden-onset (acute) episodes

When episodes of supraventricular tachycardia (SVT) start suddenly and cause symptoms, you can try vagal manoeuvres—such as gagging, holding your breath and bearing down (Valsalva manoeuvre), immersing your face in ice-cold water (diving reflex), or coughing. These simple manoeuvres stimulate the vagus nerve, which can slow conduction of electrical impulses that control your heart rate. Your doctor will teach you how to perform vagal manoeuvres safely.

Your doctor may also prescribe a short-acting medicine that you can take by mouth if vagal manoeuvres don't work. This allows some people to manage their SVT without having to visit the emergency room repeatedly.

If your heart rate cannot be slowed using vagal manoeuvres, you may have to go to your doctor's office or the emergency room, where a fast-acting medicine such as adenosine or verapamil can be given. If the arrhythmia does not stop and symptoms are severe, electrical cardioversion, which uses an electrical current to reset the heart rhythm, may be needed.

Ongoing treatment of recurring supraventricular tachycardia

If you have recurring episodes of supraventricular tachycardia, you may need to take medicines, either on an as-needed basis or daily. Medicine treatment typically includes beta-blockers, calcium channel blockers, other antiarrhythmic medicines, or digoxin. In people who have frequent episodes, treatment with medicines can decrease recurrences. But these medicines may have side effects.

Many people with supraventricular tachycardia have a procedure called catheter ablation, which blocks abnormal electric impulses and can eliminate supraventricular tachycardia and the need to take medicines. But this procedure has risks, such as bleeding and injury to the heart. You must balance your feelings about taking medicine for the rest of your life with having an invasive procedure. Also, catheter ablation is not available everywhere and is best performed in a medical centre that has staff experienced with this complicated procedure.

Click here to view a Decision Point. Heart Problems: Should I Have Catheter Ablation?

Treatment for atrioventricular nodal re-entrant tachycardia (AVNRT)

In the case of atrioventricular nodal re-entrant tachycardia (AVNRT), medicines can be taken—either daily or only when the fast heartbeat arises—or catheter ablation may be done.

If you have infrequent episodes of AVNRT that last hours but do not cause severe symptoms, your doctor may recommend that you take medicines only when you have an episode. These medicines include antiarrhythmic medicines, calcium channel blockers, and beta-blockers.

Your doctors may recommend daily doses of calcium channel blockers, beta-blockers, and/or digoxin if you have frequent episodes of AVNRT. If these medicines are not effective in stopping supraventricular tachycardia from recurring, your doctor may recommend that you take an antiarrhythmic medicine.

If you take daily medicine for AVNRT or you have significant symptoms, you may want to consider having catheter ablation.

Click here to view a Decision Point. Heart Problems: Should I Have Catheter Ablation?

Treatment for atrioventricular reciprocating tachycardia (AVRT)

In the case of atrioventricular reciprocating tachycardia (AVRT), you can take medicines for recurrent episodes either on an as-needed or daily basis, depending on how frequently they occur. These medicines—which include beta-blockers, calcium channel blockers, and digoxin—are often effective in stopping or preventing episodes of AVRT.

But in some people with a type of AVRT called Wolff-Parkinson-White (WPW) syndrome, digoxin and verapamil may result in extremely fast heart rates that can lead to light-headedness, fainting (syncope), and even death. These drugs are only dangerous when given in an emergency when someone with Wolff-Parkinson-White syndrome is having atrial fibrillation.

Treatment of WPW frequently requires antiarrhythmic medicines that slow electrical conduction over the extra connection.

Catheter ablation is often recommended for people who have WPW, especially those who have severe symptoms or also have atrial fibrillation or flutter. This procedure can successfully eliminate WPW most of the time. There is a small risk of the arrhythmia recurring even after successful ablation of WPW. But a second session of catheter ablation is usually successful.

Click here to view a Decision Point. Heart Problems: Should I Have Catheter Ablation?

Ongoing Concerns

After episodes of supraventricular tachycardia begin, they generally recur. These arrhythmias frequently stop spontaneously or with simple manoeuvres, but you may have to take medicines daily if the arrhythmias keep happening. Medicine treatment typically includes beta-blockers, calcium channel blockers, or digoxin. In people with frequent episodes, treatment with an antiarrhythmic medicine can decrease recurrences, and catheter ablation can eliminate the arrhythmia altogether.

When supraventricular tachycardia occurs in someone who has significant coronary artery disease, the heart may not receive enough blood to keep up with the demands of the increased heart rate. If this occurs, the heart may not get enough oxygen, potentially causing chest pain (angina) or a heart attack. If tachycardia is left untreated, repeated and long episodes of tachycardia can lead to heart failure. But mild supraventricular tachycardia, with rare and short episodes, does not typically lead to heart failure.

Mild supraventricular tachycardia, with short episodes that don't happen often, doesn't typically weaken the heart or lead to heart failure. But some people, such as those who have a heart valve disease, have a higher risk of getting heart failure. If tachycardia is left untreated, repeated and long episodes of tachycardia can lead to heart failure (known as a tachycardia-mediated cardiomyopathy). But this heart failure might be stopped, or reversed, if the supraventricular tachycardia is stopped with treatment.

Prevention

You can reduce your risk of having episodes of supraventricular tachycardia by avoiding certain stimulants or stressors, such as caffeine, nicotine, some medicines (for example, decongestants), illegal drugs (stimulants, like methamphetamines and cocaine), and excess alcohol.

If fast heart rates continue, long-term medicines such as beta-blockers may be used to help prevent a recurrence of the fast heart rate.

Living With Tachycardia

Home care includes monitoring your supraventricular tachycardia and trying to slow your heart when a fast heart rate occurs. To monitor your condition, you may find it helpful to keep a diary of your heart rate and your symptoms.

Check your pulse when you have symptoms, and record the information in your diary. Be aware that if your heart is beating rapidly, it may be hard to feel your pulse and get an accurate count of your actual heart rate.

By keeping a diary of your heart rate and symptoms, you may be able to identify stressors—such as drinking alcohol or smoking—that trigger episodes.

Also, it's usually important to avoid overuse of caffeine, nicotine, or alcohol and the use of illegal drugs, such as stimulants like cocaine, ecstasy, or methamphetamine. For people who are especially sensitive, even decaffeinated teas or coffee can cause supraventricular tachycardia episodes.

Decongestants that contain stimulants should also be avoided, including oxymetazoline (such as Dristan and other brands) and pseudoephedrine (such as Sudafed and other brands). Doctors also warn against using diet pills or "pep" pills (because many contain caffeine), ephedrine, ephedra, the herb ma huang, or other stimulants.

Your doctor may suggest that you try vagal manoeuvres—such as gagging, holding your breath and bearing down, or immersing your face in cold water—to slow your heart rate. Your doctor will help you learn these procedures so you can try them at home when your fast heart rate occurs.

More information

Medications

If you have symptoms, medicines may be used to treat supraventricular tachycardia.

Medication Choices

For severe symptoms, such as chest pain, shortness of breath, or feeling faint, you may be given fast-acting antiarrhythmic medicines by health professionals in the hospital emergency department, where your heart can be monitored. Fast-acting antiarrhythmic medicines commonly used to slow the heart rate during an episode include:

Long-term use of an antiarrhythmic medicine may also be needed to reduce the chance of having more episodes of supraventricular tachycardia or to reduce the heart rate during these episodes. Common medicines used for this purpose include:

Surgery

Open-heart surgery is rarely done for supraventricular tachycardia. Surgery might be done if you cannot have catheter ablation or if you are having surgery for another heart condition.

Other Treatment

An electric shock to the heart (electrical cardioversion) may be needed if you are having severe symptoms of supraventricular tachycardia and your heart rate does not return to normal using vagal manoeuvres or fast-acting medicines.

If you continue to have episodes that cause serious symptoms, a procedure called catheter ablation may be done during an electrophysiology (EP) study. During an EP study, the extra electrical pathway or cells in the heart that are causing the fast heart rate can often be identified and destroyed using catheter ablation.

Click here to view a Decision Point. Heart Problems: Should I Have Catheter Ablation?

Other Treatment Choices

Electrical Cardioversion
Catheter Ablation

Other Places To Get Help

Organizations

Canadian Cardiovascular Society
222 Queen Street
Suite 1403
Ottawa, ON  K1P 5V9
Phone: 1-877-569-3407 toll-free
(613) 569-3407
Fax: (613) 569-6574
Web Address: www.ccs.ca
 

The Canadian Cardiovascular Society works to advance the cardiovascular health and care of Canadians through leadership, research, and advocacy.


Heart and Stroke Foundation of Canada
222 Queen Street
Suite 1402
Ottawa, ON  K1P 5V9
Phone: (613) 569-4361
Fax: (613) 569-3278
Web Address: www.heartandstroke.ca
 

The Heart and Stroke Foundation of Canada works to improve the health of Canadians by preventing and reducing disability and death from heart disease and stroke through research, health promotion, and advocacy.


Heart Rhythm Society
1400 K Street NW
Suite 500
Washington, DC  20005
Phone: (202) 464-3400
Fax: (202) 464-3401
Web Address: www.hrsonline.org
 

The Heart Rhythm Society provides information for patients and the public about heart rhythm problems. The Web site includes a section that focuses on patient information. This information includes causes, prevention, tests, treatment, and patient stories about heart rhythm problems. You can use the Find a Specialist section of the Web site to search for a heart rhythm specialist practicing in your area.


U.S. National Heart, Lung, and Blood Institute (NHLBI)
P.O. Box 30105
Bethesda, MD  20824-0105
Phone: (301) 592-8573
Fax: (240) 629-3246
TDD: (240) 629-3255
Email: nhlbiinfo@nhlbi.nih.gov
Web Address: www.nhlbi.nih.gov
 

The U.S. National Heart, Lung, and Blood Institute (NHLBI) information center offers information and publications about preventing and treating:

  • Diseases affecting the heart and circulation, such as heart attacks, high cholesterol, high blood pressure, peripheral artery disease, and heart problems present at birth (congenital heart diseases).
  • Diseases that affect the lungs, such as asthma, chronic obstructive pulmonary disease (COPD), emphysema, sleep apnea, and pneumonia.
  • Diseases that affect the blood, such as anemia, hemochromatosis, hemophilia, thalassemia, and von Willebrand disease.

References

Other Works Consulted

  • Agency for Healthcare Research and Quality (2009). Comparative Effectiveness of Radiofrequency Catheter Ablation for Atrial Fibrillation (AHRQ Publication No. 09-EDC015-EF). Rockville, MD: Agency for Healthcare Research and Quality. Also available online: http://www.effectivehealthcare.ahrq.gov/reports/final.cfm.
  • Birnie D (2007). Supraventricular tachycardia. In J Gray, ed., Therapeutic Choices, 5th ed., pp. 531–543. Ottawa: Canadian Pharmacists Association.
  • Calkins H (2008). Supraventricular tachycardia: AV nodal reentry and Wolff-Parkinson-White syndrome. In V Fuster et al., eds., Hurst's The Heart, 12th ed., pp. 983–1002. New York: McGraw-Hill Medical.
  • Dorian P (2007). Ventricular tachyarrhythmias. In J Gray, ed., Therapeutic Choices, 5th ed., pp. 544–555. Ottawa: Canadian Pharmacists Association.
  • Epstein AE, et al. (2008). ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the ACC/AHA/NASPE 2002 Guideline Update for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices): Developed in Collaboration With the American Association for Thoracic Surgery and Society of Thoracic Surgeons. Circulation, 117(21): e350–e408. [Correction in Circulation, 120(5): e34–e35.]
  • Miller JM, Zipes DP (2008). Therapy for cardiac arrhythmias. In P Libby et al., eds., Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine, 8th ed., vol. 1, pp. 779–823. Philadelphia: Saunders Elsevier.
  • Olgin JE, Zipes DP (2008). Specific arrhythmias: Diagnosis and treatment. In P Libby et al., eds., Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 8th ed., volume 1, pp. 863–931. Philadelphia: Saunders Elsevier.
  • Zipes DP, et al. (2006). ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: A Report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death). Circulation, 114(10): 1088–1032.

Credits

By Healthwise Staff
Primary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine
Primary Medical Reviewer Donald Sproule, MD, CM, CCFP, FCFP - Family Medicine
Specialist Medical Reviewer John M. Miller, MD - Electrophysiology
Last Revised August 10, 2011

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