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$Unique_ID{BRK04337}
$Pretitle{}
$Title{Wolff-Parkinson-White Syndrome}
$Subject{Wolff-Parkinson-White Syndrome WPW Syndrome Preexcitation Syndrome
Accessory Atrioventricular Pathways Lown-Ganong-Levine Syndrome Sinus
Tachycardia Sick Sinus Syndrome Atrial Ectopic Tachycardia}
$Volume{}
$Log{}

Copyright (C) 1989, 1991 National Organization for Rare Disorders, Inc.

644:
Wolff-Parkinson-White Syndrome

** IMPORTANT **
It is possible that the main title of the article (Wolff-Parkinson-White
Syndrome) is not the name you expected.  Please check the SYNONYM listing to
find the alternate names and disorder subdivisions covered by this article.

Synonyms

     WPW Syndrome
     Preexcitation Syndrome
     Accessory Atrioventricular Pathways

Information on the following diseases can be found in the Related
Disorders section of this report:

     Lown-Ganong-Levine Syndrome
     Sinus Tachycardia
     Sick Sinus Syndrome
     Atrial Ectopic Tachycardia

General Discussion

** REMINDER **
The information contained in the Rare Disease Database is provided for
educational purposes only.  It should not be used for diagnostic or treatment
purposes.  If you wish to obtain more information about this disorder, please
contact your personal physician and/or the agencies listed in the "Resources"
section of this report.

Wolff-Parkinson-White Syndrome (WPW) is a genetic disorder involving
irregularities in the heartbeat (cardiac arrhythmia).  Wolff-Parkinson-White
patients have an extra conduction pathway in the heart, called the Bundle of
Kent, which excessively stimulates the ventricles.  Palpitations (sensation
of rapid or irregular beating of the heart), weakness, and shortness of
breath may occur.

Symptoms

Symptoms of Wolff-Parkinson-White patients are caused by the Bundle of Kent
causing abnormal heartbeats such as atrial flutter, atrial fibrillation, or
paroxysmal supraventricular tachycardia.  In atrial flutter, atriums of the
heart contract (tachycardia) more than the ventricles; atrial fibrillation is
a 'twitching' of the atriums instead of regular contractions.  This in turn
causes the ventricles to respond irregularly.  Symptoms that can occur from
atrial flutter and fibrillation may include irregular pulse, palpitations
(rapid heartbeat), lack of normal skin color (pallor), nausea, weakness,
faintness (syncope), and fatigue.  Paroxysmal supraventricular tachycardia is
a condition in which the heart rate suddenly increases to 100 to 200 beats
per minute.  A sudden, rapid, regular fluttering sensation and tightness in
the chest may occur.  Patients may also experience weakness, faintness,
palpitations, frequent urination (polyuria), and shortness of breath.
Attacks of chest pain (angina) may occur in older patients.

Causes

Wolff-Parkinson-White Syndrome is inherited as an autosomal dominant trait.
(Human traits including the classic genetic diseases are the product of the
interaction of two genes for that condition, one received from the father and
one from the mother.  In dominant disorders a single copy of the disease gene
(received from either the mother or father) will be expressed "dominating"
the other normal gene and resulting in appearance of the disease.  The risk
of transmitting the disorder from affected parent to offspring is fifty
percent for each pregnancy regardless of the sex of the resulting child.)

The normal heart has one conduction pathway (the Bundle of His) that
transmits electrical impulses from the small chambers of the heart (the
atriums or atria) to the large chambers of the heart (the ventricles).  These
electrical impulses cause the atriums then the ventricles to contract and
relax, pumping blood throughout the body.  Wolff-Parkinson-White patients
have an additional conduction pathway, the Bundle of Kent, which sends extra
electrical impulses from the atriums to the ventricles.  These extra
electrical impulses disrupt the normal beating of the heart to cause atrial
flutter, atrial fibrillation, or paroxysmal supraventricular tachycardia.

Affected Population

Wolff-Parkinson-White Syndrome is a rare disorder that is present at birth
(congenital).  It affects males and females in equal numbers, and symptoms
can occur at any age.

Related Disorders

Symptoms of the following heart disorders can be similar to those of Wolff-
Parkinson-White Syndrome.  Comparisons may be useful for a differential
diagnosis:

Lown-Ganong-Levine (LGL) Syndrome is a genetic disorder involving
irregularities in the heartbeat (cardiac arrhythmia) that are slightly
different from Wolff-Parkinson-White.  The ventricles receive part or all of
their electrical impulses from an irregular conduction pathway instead of
from the Bundle of His.  If LGL patients have atrial flutter, atrial
fibrillation, or paroxysmal atrial arrhythmias, then palpitations, faintness,
weakness, and nausea may occur as they do in Wolff-Parkinson-White Syndrome.

Sinus Tachycardia is a cardiac arrhythmia that causes the heartbeat to
gradually increase to over 100 beats per minute.  Sinus Tachycardia may be
caused by emotional stress, exercise, infection, and certain drugs.

Sick Sinus Syndrome is a cardiac arrhythmia characterized by irregular
atrium activity.  Excessively slow heart beat (bradycardia) and rapid heart
beat (tachycardia) usually occur.  Gradual supraventricular tachycardia,
atrial flutter, and atrial fibrillation may also occur.  Palpitations,
weakness, faintness, and nausea are common symptoms.

Atrial Ectopic Tachycardia is rapid beating of the heart that usually
occurs gradually.  It is the result of premature electrical impulses located
within the middle layer of the atrium (atrial myocardium).  Rapid, regular
fluttering sensations and tightness in the chest may occur.  Palpitations,
weakness, faintness, shortness of breath, and polyuria (increased urination)
may also occur.

Therapies:  Standard

The electrocardiogram (ECG) is a diagnostic test for Wolff-Parkinson-White
Syndrome.  This machine records the changes of electrical impulses that cross
the heart.  The ECG in Wolff-Parkinson-White patients shows particular
abnormalities.  Diagnosis may also be made with His Bundle
Electrocardiography.

Drug therapy, surgical treatment, and external electric shock (DC
conversion) may be effective in treating the irregularities in the heart beat
of Wolff-Parkinson-White Syndrome.

Quinidine and procainamide are antiarrhthymic drugs that may help control
atrial flutter, fibrillation, and paroxysmal supraventricular tachycardia
(PSVT).  PSVT's may also be controlled by cardiac drugs such as digoxin and
disopyramide, or by the sympathetic agents metaraminol and phenylephrine.

Surgical implantation of a cardiac pacemaker may control the rapid
heartbeat in PSVT's.

Application of external electric shock (DC conversion) to the body may
convert atrial flutter and fibrillation and PSVT's into regular heartbeats.

Emergency treatment of PSVT's may also involve lying down, stimulation of
gagging or vomiting, Valsalva's maneuver, or carotid sinus massage.

Any treatment should be used with extreme caution since it may increase
rather than decrease the irregularities in the heartbeat.  Radiofrequency
current (a less powerful type) is also being used to eliminate tachycardia in
Wolff-Parkinson-White patients.

Genetic counseling may be of benefit for patients and their families.
Other treatment is symptomatic and supportive.

Therapies:  Investigational

The drug Edrophonium, may be helpful in treatment of paroxysmal
supraventricular tachycardia (PSVT) in Wolff-Parkinson-White patients, but it
has not yet been approved by the Food and Drug Administration (FDA).

Researchers are investigating propranolol, a noradrenaline blocking drug,
that may be useful in preventing atrial flutter, fibrillation, and PSVT's.
Adenosine triphosphate (ATP), a natural molecule in the body used to store
energy, is being investigated as a treatment for PSVT's and to prevent extra
stimulation of the ventricles by the Bundle of Kent.

Flecainide, an antiarrhythmic drug, is also being studied to treat PSVT's
in Wolff-Parkinson-White patients.

This disease entry is based upon medical information available through
June 1991.  Since NORD's resources are limited, it is not possible to keep
every entry in the Rare Disease Database completely current and accurate.
Please check with the agencies listed in the Resources section for the most
current information about this disorder.

Resources

For more information on Wolff-Parkinson-White Syndrome, please contact:

     National Organization for Rare Disorders (NORD)
     P.O. Box 8923
     New Fairfield, CT  06812-1783
     [phone]

     American Heart Association
     7320 Greenville Avenue
     Dallas, TX  75231
     [phone]

     NIH/National Heart, Blood & Lung Institute
     9000 Rockville Pike
     Bethesda, MD  20892
     [phone]

For genetic information and genetic counseling referrals:

     March of Dimes Birth Defects Foundation
     1275 Mamaroneck Avenue
     White Plains, NY  10605
     [phone]

     Alliance of Genetic Support Groups
     35 Wisconsin Circle, Suite 440
     Chevy Chase, MD  20815
     (800) 336-GENE
     [phone]

References

MENDELIAN INHERITANCE IN MAN, 7th ed.:  Victor A. McKusick; Johns Hopkins
University Press, 1986.  Pp. 771.

INTERNAL MEDICINE, 2nd Ed.:  Jay H. Stein, ed.-in-chief; Little, Brown
and Co., 1987.  Pp. 375-394.

COMPARATIVE QUANTITATIVE ELECTROPHYSIOLOGIC EFFECTS OF ADENOSINE
TRIPHOSPHATE ON THE SINUS NODE AND ATRIOVENTRICULAR NODE:  A.D. Sharma & G.J.
Klein;  Am J Cardiol (February 1, 1988:  issue 61(4)).  Pp. 330-335.