Alternative Names PSVT, supraventricular tachycardia, SVT, paroxysmal atrial tachycardia
Definition Paroxysmal supraventricular tachycardia, or PSVT, is an abnormal, fast heartbeat that occurs suddenly. It is triggered in the atria, or upper chambers, of the heart.
What is going on in the body? The heart has a built-in electrical system. Special pacemaker cells in the heart generate electrical impulses. These cells send electrical current down pathways in the heart muscle. When this occurs at the proper time, a normal heart rhythm is produced. When the electrical current starts in the wrong place or goes in the wrong direction at the wrong time, an abnormal heart rhythm, or arrhythmia, results. PSVT occurs when electrical current flows in a circle instead of a line. The result is a rapid heart rate, generally 160 to 180 beats per minute.
What are the signs and symptoms of the condition? The signs and symptoms of PSVT include:
palpitations, or unusual awareness of the heart beating in the chest
What are the causes and risks of the condition? A faulty electrical pathway in the heart causes PSVT. It may be triggered by physical or psychological stress. The risks from PSVT are minimal for otherwise healthy people. Most people require very little, if any, medical intervention. PSVT may cause symptoms in older people with weak hearts or coronary artery disease. In some people, PSVT can cause congestive heart failure or a heart attack. Some people have regular episodes of PVST due to an abnormal development of the electrical pathways present at birth. An example of this is a condition called Wolff-Parkinson-White syndrome.
What can be done to prevent the condition? Someone who experiences PSVT can be taught simple methods to help stop it. These techniques can be as simple as holding one's breath or straining down very hard. Some people may take medications only when an episode of PSVT occurs, while others may take medication daily to prevent episodes.
PSVT can be prevented by a procedure called radiofrequency catheter ablation. In this procedure, a specially trained heart specialist or cardiologist places a small tube or catheter in the heart to find the circular electrical pathway. Radio waves are used to eliminate the abnormal electrical pathway. This usually prevents any more episodes of PSVT from occurring.
How is the condition diagnosed? PSVT is diagnosed with an electrocardiogram, or ECG. An ECG records the electrical activity of the heart. The doctor diagnoses PSVT after reviewing the ECG.
What are the long-term effects of the condition? PSVT is usually more of a bother than an illness. Many people who experience PSVT can stop the abnormal rhythm with the techniques taught by their doctor. The abnormal heart rhythm may correct itself. Other people may need to go to the emergency department to get medication for episodes of PVST.
What are the risks to others? There are no risks to others.
What are the treatments for the condition? Someone who experiences PSVT for the first time usually goes to the emergency department. Simple techniques often stop the PSVT. When these methods don't stop the PSVT, a medication called adenosine may be tried. This medication is given in the vein of the person with PSVT. Usually within a few seconds, the medication disrupts the abnormal electrical pathway, resulting in the return of a normal heart rhythm.
What are the side effects of the treatments? If medication is needed, side effects may be experienced. Complications from radiofrequency catheter ablation are rare, but may include blood clots, new arrhythmias, or even a heart attack. Occasionally, a person may need a permanent pacemaker after this procedure.
What happens after treatment for the condition? Once PSVT stops and the heart returns to a normal rate and rhythm, the person is the same as they were before the onset of PSVT. If a person has frequent or disabling PSVT, the doctor may recommend radiofrequency catheter ablation.
How is the condition monitored? Generally, monitoring is not done for PSVT. A person who experiences PSVT should notify the doctor if the frequency or severity of the episodes changes.
Author: Jeffrey La Flamme, DC Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
