WOLFF-PARKINSON-WHITE SYNDROME (WPWS)
Wolff-Parkinson-White Syndrome (WPWS) is a disorder in which an extra
electrical connection between the atria and the ventricles is present at
birth. People may have episodes of a very rapid heartbeat.
People
with WPWS are born with an extra connection in the heart, called an
accessory pathway, that allows electrical signals to bypass the
trioventricular node and move from the atria to the ventricles faster
than usual. The accessory pathway may also transmit electrical impulses
disrupt the coordinated movement of electrical signals through the
heart, abnormally from the ventricles back to the atria. This extra
connection can leading to an abnormally fast heartbeat (tachycardia) and
other arrhythmias.
The
heartbeat is controlled by electrical signals that move through the
heart in a highly coordinated way. A specialized cluster of cells called
the atrioventricular node conducts electrical impulses from the heart's
upper chambers (the atria) to the lower chambers (the ventricles). Impulses move through the atrioventricular node during each heartbeat,
stimulating the ventricles to contract slightly later than the atria.
WPWS is
the most common of several disorders that involve an extra (accessory)
pathway between the atria and the ventricles. (Such disorders are called atrioventricular reciprocating supraventricular tachycardias.) This
extra pathway makes fast arrhythmias more likely to occur. WPW syndrome
changes the pattern of electrical activation in the heart and can be
diagnosed using electrocardiography.
Atrial
fibrillation may be particularly dangerous for people with
Wolff-Parkinson-White syndrome. The extra pathway can conduct the rapid
impulses to the ventricles at a much faster rate than the normal pathway
(through the atrioventricular node) can. The result is an extremely fast
ventricular rate that may be life threatening. Not only is the heart
very inefficient when it beats so rapidly, but this extremely fast heart
rate may also progress to ventricular fibrillation, which is fatal
unless treated immediately.
Symptoms:
Symptoms
may include dizziness, a sensation of fluttering or pounding in the
chest (palpatations), shortness of breath, and fainting (syncope). In
rare cases, arrhythmias associated with Wolff-Parkinson-White syndrome
can lead to cardiac arrest and sudden death. The most common arrhythmia
associated with Wolff-Parkinson-White syndrome is called paroxysmal supraventricular tachycardia.. Very rarely, this syndrome results in a
very fast, life-threatening heart rate during atrial fibrillation.
WPWS is present at birth, but the arrhythmias it causes usually become
apparent during the teens or early twenties. However, arrhythmias may
occur during the first year of life or not until after age 60.
When infants develop arrhythmias due to this syndrome, they may become
short of breath or lethargic, stop eating well, or have rapid, visible
pulsations of the chest. Heart failure may develop.
Typically, when teenagers or people in their early 20s first experience
an arrhythmia due to this syndrome, it is an episode of palpitations
that begins suddenly, often during exercise. The episode may last for
only a few seconds or may persist for several hours. For most people,
the very fast heart rate is uncomfortable and distressing. A few people
faint.
In older
people, episodes of paroxysmal supraventricular tachycardia due to
Wolff-Parkinson-White syndrome tend to produce more symptoms, such as
fainting, shortness of breath, and chest pain.
Additional
Resources:
The
Cleveland Clinic Heart Center
http://www.clevelandclinic.org/heartcenter/pub/guide/disease/electric/wpw.htm
The Mayo
Clinic
www.mayoclinic.com/health/wolff-parkinson-white-syndrome/DS00923/DSECTION=3
