Paroxysmal Supraventricular Tachycardia (PVST)

What Is Paroxysmal Supraventricular Tachycardia?

Paroxysmal supraventricular tachycardia (PSVT) is a faster-than-normal heart rate. The term paroxysmal means that it only happens from time to time. In the case of PSVT, the rapid heart rate can last from a few minutes to several hours. PSVT is a fairly common type of irregular heartbeat (arrhythmia) that can occur in a person of any age, even one who does not have any other heart conditions.

In PSVT, the hearts sinus node, which sends electrical signals to tell the heart muscle when to contract, “short-circuits,” causing beats to occur more frequently than normal. The heart rate of a patient with PSVT can be as high as 250 beats per minute (bpm). A normal rate is between 60 and 100 bmp.

PSVT can result in uncomfortable symptoms, but it is not life threatening unless you have other heart conditions. Most people do not require treatment for PSVT. However, there are medications and procedures that can relieve symptoms or cure the disorder in cases where the rapid heart rate interferes with normal heart function.

What Are the Risk Factors for Paroxysmal Supraventricular Tachycardia?

PSVT is more common in children and younger adults than in older adults. You increase your risk of experiencing PSVT by ingesting caffeine, alcohol, and illegal drugs, and by smoking.

There are also certain medications and conditions that can cause PSVT. The heart medication digitalis can lead to episodes of PSVT when taken in large doses.

Wolff-Parkinson-White syndrome is the most common cause of PSVT in children and infants. Someone with this disorder has an extra electrical pathway, or circuit, in the heart that leads to a rapid heartbeat. In a normal heart, the sinus node directs electrical signals through one specific pathway, which regulates the frequency of your heartbeats. An extra pathway, as is present in patients with Wolff-Parkinson-White syndrome, causes the fast heartbeat of PSVT.

Symptoms of Paroxysmal Supraventricular Tachycardia

The symptoms of PSVT are not life threatening. They are similar to symptoms of an anxiety attack and include:

  • heart palpitations
  • a rapid pulse
  • a feeling of tightness or pain in the chest
  • anxiety
  • shortness of breath

In more serious cases, PSVT can cause dizziness and even fainting.

Sometimes, a patient with symptoms of PSVT may confuse the condition with a heart attack, especially if this is his or her first PSVT episode. If chest pain is severe and you are not sure whether or not you are having a heart attack, you should go to the emergency room for testing to rule out anything serious.

How Is Paroxysmal Supraventricular Tachycardia Diagnosed?

If you have an episode of fast heartbeats during an examination, your doctor will be able to measure your heart rate. If it is very high, he or she may suspect PSVT.

To diagnose PSVT, your doctor may order an intracardiac electrophysiology study (EPS). This will involve threading wires through a vein in your groin and up into your heart to place electrodes that will monitor the hearts rhythm. The EPS test allows your doctor to evaluate the electrical pathways of your heart.

Your doctor may also choose to monitor your heart rate over a longer period of time. In this case, you will be asked to wear a Holter monitor for 24 hours. During that time, you will have sensors attached to your chest and will wear the monitor around your waist, recording your heart rate. Your doctor will then look over the recordings to determine if you have PSVT.

How Is Paroxysmal Supraventricular Tachycardia Treated?

If your symptoms are minimal and you only have a rapid heart rate occasionally, you may not need treatment. But, if you have an underlying condition causing the PSVT or more severe symptoms, treatment may be necessary.

If you have a rapid heart rate often, but your symptoms are not severe, your doctor can show you a technique for restoring your heart rate to normal. This is called the Valsalva maneuver. It involves holding your breath and straining as if you were trying to have a bowel movement while sitting with your body bent forward. You can perform this maneuver at home once you learn how to do it.

Treatments for PSVT may include medications, such as propafenone, to help make your heartbeat more regular. A procedure called radiofrequency catheter ablation is a common way to correct the PSVT permanently. It is performed in the same way as an EPS test. It will allow the doctor to use electrodes to destroy tissue in the heart muscle that is causing the “short circuit” of PSVT.

If your PSVT does not respond to other treatments, a pacemaker device may be surgically implanted in your chest to regulate your heart rate.

What Is the Outlook for Paroxysmal Supraventricular Tachycardia?

In most cases, the outlook for PSVT is very good. As long as your doctor can rule out any underlying heart conditions, PSVT is not life threatening. If you do have other heart conditions, your outlook depends on what they are and which treatments are available.

Unfortunately, having PSVT raises your risk for experiencing heart failure in the future.