Ventricular Tachycardia

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Ventricular Tachycardia

Topic Overview

If you have supraventricular tachycardia (SVT), go to the topic Supraventricular Tachycardia.

What is ventricular tachycardia?

Ventricular tachycardia is a fast heart rhythm that starts in the lower part of the heart (ventricles). If left untreated, some forms of ventricular tachycardia may get worse and lead to ventricular fibrillation, which can be life-threatening.

Ventricular tachycardia is a fast but regular rhythm. It can lead to ventricular fibrillation which is fast and irregular. With ventricular fibrillation, the heart beats are so fast and irregular that the heart stops pumping blood. Ventricular fibrillation is a leading cause of sudden cardiac death.

What causes ventricular tachycardia?

Sometimes it is not known what causes ventricular tachycardia, especially when it occurs in young people. But in most cases ventricular tachycardia is caused by heart disease, such as a previous heart attack, a congenital heart defect, hypertrophic or dilated cardiomyopathy, or myocarditis. Sometimes ventricular tachycardia occurs after heart surgery.

Some medicines—including antiarrhythmic medicines, which are used to treat other types of abnormal heart rhythms—can cause ventricular tachycardia. Less common causes include blood imbalances, such as low potassium levels and other electrolyte imbalances.

Non-prescription decongestants, herbal remedies (especially those that contain ma huang or ephedra), diet pills, and "pep" pills often contain stimulants that can trigger episodes of ventricular tachycardia. Illegal drugs (such as stimulants, like cocaine) also may cause ventricular tachycardia. It is important to be aware of which substances have an effect on you and how to avoid them.

What are the symptoms?

In ventricular tachycardia, the heart beats too rapidly and the ventricles cannot effectively pump oxygen-rich blood to the rest of the body. Ventricular tachycardia can be life-threatening.

Symptoms include:

This heart rhythm is dangerous for most people. If it lasts more than just a few seconds, it can turn into ventricular fibrillation which causes sudden death.

How is ventricular tachycardia diagnosed?

If an electrocardiogram (EKG, ECG) can be performed while ventricular tachycardia is occurring, it often provides the most useful information. An electrocardiogram is a tracing of the electrical activity of your heart. It is usually done along with a history and physical examination, lab tests, and a chest X-ray.

Because ventricular tachycardia can occur intermittently and may not always be captured by an EKG at the doctor's office, you may be asked to use a portable EKG to record your heart rhythm on a continuous basis, usually over a 24-hour period. This is referred to by several names, including ambulatory electrocardiography, ambulatory EKG, Holter monitoring, 24-hour EKG, or cardiac event monitoring.

Your doctor may recommend further tests, including an echocardiogram, to evaluate your heart's function, a stress test or coronary angiogram to determine whether a part of the heart is not getting enough blood, and/or an electrophysiology study. During an electrophysiology (EP) study, electrical currents are sent through a catheter into the heart to try to trigger ventricular tachycardia and record the flow of electricity through the heart. In this way, the EP study can locate specific areas of heart tissue that give rise to abnormal electrical impulses, which may be causing the ventricular tachycardia. This information is used to determine the best treatment.

How is it treated?

If you are having symptoms and are in a sustained tachycardia, it is a medical emergency. You will require immediate treatment. You may need CPR or a shock from an automatic defibrillator (also known as an AED). Paramedics or your doctor may try intravenous medicines or electrical cardioversion to return your heart to a normal rhythm.

To prevent the arrhythmia from recurring, you may need to take antiarrhythmic medicines. But these medicines may have side effects. So instead, doctors often recommend a type of permanent pacemaker, called an implantable cardioverter defibrillator (ICD). This device is placed under the skin in your chest and continuously monitors your heart's rhythm. If ventricular tachycardia occurs, the ICD applies an electrical shock to the heart to restore a normal rhythm. After a normal rhythm is restored, the device goes back to continuous monitoring mode. Sometimes, both medicines and an ICD are needed.

Click here to view a Decision Point. Heart Rate Problems: Should I Get an ICD?

In some cases a procedure called catheter ablation is used to destroy small areas of heart tissue responsible for the arrhythmia. In this procedure, thin, flexible wires are inserted into a blood vessel in the thigh, groin, neck, or elbow and threaded to the heart. Through these wires, heat or freezing cold temperatures can be delivered to the specific heart tissue that is generating abnormal electrical impulses (previously located in the EP study). The heat or freezing cold destroy (ablate) this heart tissue and can stop ventricular tachycardia from happening again.

It is very important that any causes of ventricular tachycardia be identified and treated, if possible. For example, if the ventricular tachycardia results from a medicine, the medicine needs to be stopped.

What precautions should you take?

If you have had an episode of ventricular tachycardia or ventricular fibrillation, your doctor may recommend that you don't drive a car for a few months. This precaution is to make sure you don't have any other episodes that could make driving unsafe.

If you want to lose weight, do not use diets that rely on a liquid-based program or a high-protein regimen. These types of diets can affect the concentrations of electrolytes in your blood. This can, in turn, cause problems with your heart.

When to call a doctor

If you have palpitations, dizziness, near-fainting, or chest pain, call 911 or other emergency services immediately.

If you have an ICD

If you have an ICD, be sure you have a plan for what to do if you get a shock. Talk to your doctor if you need to make a plan. In general, your plan depends on how you feel after you get a shock and how many times you get a shock.

After one shock:

  • Call 911 or other emergency services immediately if you feel bad or have symptoms like chest pain.
  • Call your doctor soon if you feel fine right way. Your doctor may want to talk about the shock and schedule a follow-up visit.

After a second shock within 24 hours:

  • Call your doctor immediately, even if you feel fine right away.

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

  • Epstein AE, et al. (1996). Personal and public safety issues related to arrhythmias that may affect consciousness: Implications for regulation and physician recommendations. A medical/scientific statement from the American Heart Association and the North American Society of Pacing and Electrophysiology. Circulation, 94(5): 1147–1166.
  • Epstein AE, et al. (2007). Addendum to Personal and public safety issues related to arrhythmias that may affect consciousness: Implications for regulation and physician recommendations: A medical/scientific statement from the American Heart Association and the North American Society of Pacing and Electrophysiology. Public safety issues in patients with implantable defibrillators. A scientific statement from the American Heart Association and the Heart Rhythm Society. Circulation, 115(9): 1170–1176.
  • 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.]
  • 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 November 26, 2010

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