Patient
Information
Supraventricular Tachycardia (SVT)
- Instructions
Paroxysmal
Supraventricular Tachycardia, or SVT for short, is an abnormal
heart rhythm in which the heart beats at a fast rate, usually
between 200 and 320 beats per minute in young children and 160 to
200 beats per minute in teenagers.
This is a common problem, and is not usually dangerous
unless the rate is very high or the fast rate continues for a very
long period of time. In
addition, the rate is usually the same every time for each
individual child.
The
symptoms of SVT depend a lot on the age of the child, but usually
only involve a feeling of a “racing heart” (palpitations),
nausea and/or chest pain. Symptoms
which are more concerning include:
|
Older
Children
·
shortness of
breath
·
dizziness
·
fainting
|
Infants
·
Paleness
·
Irritability
·
poor feeding
·
rapid or
difficult breathing
·
passing out
|
If
any of these signs or symptoms occur, contact your physician
immediately.
There
are several ways to convert an episode of SVT back to normal heart
rhythm. Methods you
can use at home include “tricks” called “vagal maneuvers”,
because they increase the activity of the vagus nerve.
These include:
·
Any maneuver that
makes the face red. Examples
include “bearing down” (as one would to have a bowel
movement), hanging the head and upper body off the end of a bed or
couch, or even a head-stand or hanging upside down (if done
carefully with supervision).
·
Causing a gag reflex
by pushing down gently on the back of the tongue with a finger,
tongue depressor or spoon. This
may be tried by the patient, but it can be hazardous for other
people to perform.
·
Putting ice and
water, usually in a Zip Lock bag, over the patient’s forehead
and the bridge of the nose. Care
must be taken not to cover the nose, and the ice should be applied
for no more than 30 seconds to avoid the risk of frostbite.
Some
maneuvers used in the past have since been shown to be dangerous
and are no longer used. Please
limit yourself to the maneuvers listed above.
If
vagal maneuvers fail to convert the rhythm, and the episode
continues for more than a half an hour or any of the concerning
signs or symptoms occur, it is appropriate to call your physician
or go to an emergency room.
Questions?
Please don’t hesitate to contact me if you have any additional
questions about your child’s heart.
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