URL of this page: //medlineplus.gov/ency/article/000187.htm

Ventricular tachycardia

Ventricular tachycardia (VT) is a rapid heartbeat that starts in the lower chambers of the heart (ventricles).

Causes

VT is a pulse rate of more than 100 beats per minute, with at least 3 irregular heartbeats in a row.

The condition can develop as an early or late complication of a heart attack. It may also occur in people with:

VT can occur without heart disease.

Scar tissue may form in the muscle of the ventricles days, months, or years after a heart attack. This can lead to ventricular tachycardia.

VT can also be caused by:

  • Anti-arrhythmic drugs (used to treat an abnormal heart rhythm)
  • Changes in blood chemistry (such as a low potassium level)
  • Changes in pH (acid-base)
  • Lack of enough oxygen

"Torsade de pointes" is a form of VT. It is often due to congenital heart disease or the use of certain medicines.

Symptoms

You may have symptoms if the heart rate during a VT episode is very fast or lasts longer than a few seconds. Symptoms may include:

Symptoms may start and stop suddenly. In some cases, there are no symptoms.

Exams and Tests

The health care provider will look for:

  • Absent pulse
  • Loss of consciousness
  • Normal or low blood pressure
  • Rapid pulse

Tests that may be used to detect ventricular tachycardia include:

You may also have blood chemistries and other tests.

Treatment

Treatment depends on the symptoms, and the type of heart disorder.

If someone with VT is in distress, they may require:

  • CPR
  • Cardioversion (electric shock)
  • Medicines (such as lidocaine, procainamide, sotalol, or amiodarone) given through a vein

After an episode of VT, steps are taken to further episodes.

  • Medicines taken by mouth may be needed for long-term treatment. However, these drugs may have severe side effects. They are being used less often as other treatments are developed.
  • A procedure to destroy the heart tissue that is causing the abnormal heartbeat (called ablation) may be done.
  • An implantable cardioverter defibrillator (ICD) may be used. It  is a device that detects any life-threatening, rapid heartbeat. This abnormal heartbeat is called an arrhythmia. If it occurs, the ICD quickly sends an electrical shock to the heart to change the rhythm back to normal. This is called defibrillation.
Implantable cardiac defibrillator

Outlook (Prognosis)

The outcome depends on the heart condition and symptoms.

Possible Complications

Ventricular tachycardia may not cause symptoms in some people. However, it can be deadly. It is a major cause of sudden cardiac death.

When to Contact a Medical Professional

Go to the emergency room or call the local emergency number (such as 911) if you have a rapid, irregular pulse; faint, or have chest pain. All of these may be signs of ventricular tachycardia.

Prevention

In some cases, the disorder cannot be prevented. In other cases, it can be prevented by treating heart problems and avoiding certain medicines.

Alternative Names

Wide-complex tachycardia; V tach; Tachycardia - ventricular

References

Garan H. Ventricular arrhythmias. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 65.

Olgin JE, Zipes DP. Specific Arrhythmias: diagnosis and treatment. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 10th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 37.

Tracy CM, Epstein AE, Darbar D, et al. 2012 ACCF/AHA/HRS focused update of the 2008 guidelines for device-based therapy of cardiac rhythm abnormalities: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2012;60(14):1297-1313. PMID: 23265327 www.ncbi.nlm.nih.gov/pubmed/23265327.

Update Date 5/5/2016

Updated by: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

Related MedlinePlus Health Topics