MSD Manual

Please confirm that you are not located inside the Russian Federation

Loading

Paroxysmal Supraventricular Tachycardia (SVT, PSVT)

By

L. Brent Mitchell

, MD, Libin Cardiovascular Institute of Alberta, University of Calgary

Last full review/revision Jul 2019| Content last modified Jul 2019
Click here for the Professional Version
GET THE QUICK FACTS

Paroxysmal supraventricular tachycardia is a regular, fast (160 to 220 beats per minute) heart rate that begins and ends suddenly and originates in heart tissue other than that in the ventricles.

  • Most people have uncomfortable awareness of heartbeats (palpitations), shortness of breath, and chest pain.

  • Episodes can often be stopped by maneuvers that stimulate the vagus nerve, which slows the heart rate.

  • Sometimes, people are given drugs to stop the episode.

Paroxysmal supraventricular tachycardia is most common among young people and is more unpleasant than dangerous. It may occur during vigorous exercise.

Paroxysmal supraventricular tachycardia may be triggered by a premature heartbeat that repeatedly activates the heart at a fast rate. This repeated, rapid activation may be caused by several abnormalities. There may be two electrical pathways in the atrioventricular node (an abnormal heart rhythm [arrhythmia] called atrioventricular nodal reentrant supraventricular tachycardia). There may be an abnormal electrical pathway between the atria and the ventricles (an arrhythmia called atrioventricular reciprocating supraventricular tachycardia). Much less commonly, the atria may generate abnormal rapid or circling impulses (an arrhythmia called true paroxysmal atrial tachycardia).

The fast heart rate tends to begin and end suddenly and may last from a few minutes to many hours. It is almost always experienced as an uncomfortable awareness of the heartbeat, such as feeling like the heart is pounding or racing (palpitations). It is often associated with other symptoms, such as weakness, light-headedness, shortness of breath, and chest pain. Usually, the heart is otherwise normal.

The doctor confirms the diagnosis by doing electrocardiography (ECG).

Treatment

  • Maneuvers and drugs to slow heart rate or restore a normal rhythm

  • Sometimes radiofrequency ablation

Episodes of paroxysmal supraventricular tachycardia often can be stopped by one of several maneuvers that stimulate the vagus nerve and thus decrease the heart rate. These maneuvers are usually conducted or supervised by a doctor, but people who repeatedly experience the arrhythmia often learn to do the maneuvers themselves. Maneuvers include

  • Straining as if having a difficult bowel movement

  • Rubbing the neck just below the angle of the jaw (which stimulates a sensitive area on the carotid artery called the carotid sinus)

  • Plunging the face into a bowl of ice-cold water

These maneuvers are most effective when they are used shortly after the arrhythmia starts.

If these maneuvers are not effective, if the arrhythmia causes severe symptoms, or if the episode lasts more than 20 minutes, people are advised to seek medical intervention to stop the episode. Doctors can usually stop an episode promptly by giving an intravenous injection of a drug, usually adenosine or verapamil. Rarely, drugs are ineffective, and cardioversion (delivery of an electrical shock to the heart) may be necessary.

Prevention is more difficult than treatment. When episodes are frequent or bothersome, doctors usually recommend catheter ablation. For this procedure, energy that has a specific frequency or cold is delivered through a catheter inserted in the heart. This energy or cold temperature destroys the tissue in which paroxysmal supraventricular tachycardia originates.

If catheter ablation is not an option, almost any antiarrhythmic drug may be effective. Drugs commonly used include beta-blockers, digoxin, diltiazem, verapamil, propafenone, and flecainide (see table Some Drugs Used to Treat Arrhythmias).

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version

Also of Interest

Videos

View All
The Heart
Video
The Heart
3D Models
View All
The Coronary Arteries
3D Model
The Coronary Arteries

SOCIAL MEDIA

TOP