What is paroxysmal supraventricular tachycardia?
Episodes of faster-than-normal heart rate
characterize paroxysmal supraventricular tachycardia (PSVT). PSVT is a fairly
common type of abnormal heart rate. It can occur at any age and in people who
don’t have other heart conditions.
The heart’s sinus node typically sends
electrical signals to tell the heart muscle when to contract. In PSVT, an
abnormal electrical pathway causes the heart to beat faster than normal.
Episodes of rapid heart rate can last from a few minutes to several hours. A
person with PSVT can have a heart rate as high as 250 beats per minute (bpm). A
normal rate is between 60 and 100 bpm.
PSVT can cause uncomfortable symptoms, but
it’s not usually life-threatening. Most people don’t need long-term treatment
for PSVT. There are medications and procedures that may be necessary in some
cases, especially where PSVT interferes with heart function.
“paroxysmal” means that it only happens from time to time.
What are the risk
factors for paroxysmal supraventricular tachycardia?
PSVT affects about 1 in every 2,500 children.
It is the most frequent abnormal heart rhythm in newborns and infants. Wolff-Parkinson-White syndrome (WPW) is the most common type of PSVT in children and infants.
PSVT is more common in adults under age 65.
Adults over age 65 are more likely to have atrial fibrillation (AFib).
In a normal heart, the sinus node directs
electrical signals through a specific pathway. This regulates the frequency of
your heartbeats. An extra pathway, often present in supraventricular
tachycardia, can lead to the abnormally fast heartbeat of PSVT.
There are certain medications that make PSVT
more likely. For example, when taken in large doses, the heart medication
digitalis (digoxin) can lead to episodes of PSVT. The following actions can also increase your
risk of having an episode of PSVT:
- using illegal
- taking certain
allergy and cough medications
What are the symptoms
of paroxysmal supraventricular tachycardia?
The symptoms of PSVT resemble the symptoms of
an anxiety attack and can include:
In more serious cases, PSVT can cause
dizziness and even fainting due to poor blood flow to the brain.
Sometimes, a person experiencing symptoms of
PSVT may confuse the condition with a heart attack. This is especially true if
it’s their first PSVT episode. If your chest pain is severe you should always go
to the emergency room for testing.
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’s very high, they may suspect PSVT.
To diagnose PSVT, your doctor will order an electrocardiogram (EKG). This is an
electrical tracing of the heart. It can help determine which type of rhythm
problem is causing your fast heart rate. PSVT is only one of many causes of abnormally
fast heartbeats. Your doctor will also likely order an echocardiogram, or ultrasound of the heart, to evaluate the size, movement, and
structure of your heart.
If you have an abnormal heart rhythm or rate,
your doctor may refer you to a specialist who is an expert in electrical
problems of the heart. They are known as electrophysiologists or EP
cardiologists. They may perform an electrophysiology study (EPS). This
will involve threading wires through a vein in your groin and up into your
heart. This will allow your doctor to evaluate your heart’s rhythm by checking
the electrical pathways of your heart.
Your doctor may also monitor your heart rate
over a period of time. In this case, you may wear a Holter monitor for 24 hours
or longer. During that time, you’ll have sensors attached to your chest and
will wear a small device that records your heart rate. Your doctor will assess
the recordings to determine if you have PSVT or some other type of abnormal
How is paroxysmal
supraventricular tachycardia treated?
You might not need treatment if your symptoms
are minimal or if you only have episodes of rapid heart rate occasionally.
Treatment may be necessary if you have an underlying condition causing the PSVT
or more severe symptoms like heart failure or passing out.
If you have a rapid heart rate but your symptoms
aren’t severe, your doctor can show you techniques to return your heart rate to
normal. It’s called the Valsalva maneuver. It
involves closing your mouth and pinching your nose while trying to exhale and
straining as if you were trying to have a bowel movement. You should do this
while sitting and bending your body forward.
You can perform this maneuver at home. It may
work up to 50 percent of the time. You can also try coughing while sitting and
bending forward. Splashing ice water on your face is another technique to help lower
your heart rate.
Treatments for PSVT include medications, such
as or flecainide or propafenone, to help regulate your
heartbeat. A procedure called radiofrequency catheter ablation is a
common way to correct PSVT permanently. It’s performed in the same way as an
EPS. It allows your doctor to use electrodes to disable the electrical pathway
that’s causing the PSVT.
If your PSVT doesn’t respond to other
treatments, your doctor may surgically implant a pacemaker into your chest to regulate your heart rate.
What is the outlook
for paroxysmal supraventricular tachycardia?
PSVT is not life-threatening. However, if you
have an underlying heart condition, PSVT could increase your risk of congestive
heart failure, angina, or other abnormal rhythms. Remember that your outlook
depends on your overall health and available treatment options.