Wolff-Parkinson-White syndrome: A condition caused by an abnormality in the electrical system of the heart which normally tells the heart muscle when to contract. In Wolff-Parkinson-White (WPW) syndrome, there is an extra electrical connection inside the heart that acts as a short circuit, causing the heart to beat too rapidly and sometimes in an irregular manner. The syndrome can be lifethreatening although this is unusual.
WPW can be treated by destroying the short circuit using a technique termed radiofrequency catheter ablation in which wires are placed in different places in the heart until the short circuit is found and can be destroyed with radiowaves.
WPW involves preexcitation. Part of the venetricle receives premature electrical stimulation due to the presence of an accessory pathway (the short circuit) which is not subject to the normal delay at the atrioventricular node.
Wolff-Parkinson-White is written with hyphens because the syndrome was not discovered by a Dr. Wolff Parkinson White but by three doctors: Louis Wolff, Sir John Parkinson, and Paul Dudley White.
What is Wolff-Parkinson-White syndrome?
Wolff-Parkinson-White syndrome is a condition characterized by abnormal electrical pathways in the heart that cause a disruption of the heart's normal rhythm (arrhythmia).
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.
People with Wolff-Parkinson-White syndrome are born with an extra connection in the heart, called an accessory pathway, that allows electrical signals to bypass the atrioventricular node and move from the atria to the ventricles faster than usual. The accessory pathway may also transmit electrical impulses abnormally from the ventricles back to the atria. This extra connection can disrupt the coordinated movement of electrical signals through the heart, leading to an abnormally fast heartbeat (tachycardia) and other arrhythmias. Resulting symptoms include dizziness, a sensation of fluttering or pounding in the chest (palpitations), 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.
Complications of Wolff-Parkinson-White syndrome can occur at any age, although some individuals born with an accessory pathway in the heart never experience any health problems associated with the condition.
Wolff-Parkinson-White syndrome often occurs with other structural abnormalities of the heart or underlying heart disease. The most common heart defect associated with the condition is Ebstein anomaly, which affects the valve that allows blood to flow from the right atrium to the right ventricle (the tricuspid valve). Additionally, Wolff-Parkinson-White syndrome can be a component of several other genetic syndromes, including hypokalemic periodic paralysis (a condition that causes episodes of extreme muscle weakness), Pompe disease (a disorder characterized by the storage of excess glycogen), and tuberous sclerosis (a condition that results in the growth of noncancerous tumors in many parts of the body).
Read more about hypokalemic periodic paralysis; tuberous sclerosis complex; and Pompe disease.
Wolff-Parkinson-White syndrome affects 1 to 3 in 1,000 people worldwide. Only a small fraction of these cases appear to run in families.
Wolff-Parkinson-White syndrome is a common cause of an arrhythmia known as paroxysmal supraventricular tachycardia. Wolff-Parkinson-White syndrome is the most frequent cause of this abnormal heart rhythm in the Chinese population, where it is responsible for more than 70 percent of cases.
Mutations in the PRKAG2 gene cause Wolff-Parkinson-White syndrome.
A small percentage of all cases of Wolff-Parkinson-White syndrome are caused by mutations in the PRKAG2 gene. Some people with these mutations also have features of hypertrophic cardiomyopathy, a form of heart disease that enlarges and weakens the heart (cardiac) muscle. The PRKAG2 gene provides instructions for making a protein that is part of an enzyme called AMP-activated protein kinase (AMPK). This enzyme helps sense and respond to energy demands within cells. It is likely involved in the development of the heart before birth, although its role in this process is unknown.
Researchers are uncertain how PRKAG2 mutations lead to the development of Wolff-Parkinson-White syndrome and related heart abnormalities. Research suggests that these mutations alter the activity of AMP-activated protein kinase in the heart, although it is unclear whether the genetic changes overactivate the enzyme or reduce its activity. Studies indicate that changes in AMP-activated protein kinase activity allow a complex sugar called glycogen to build up abnormally within cardiac muscle cells. Other studies have found that altered AMP-activated protein kinase activity is related to changes in the regulation of certain ion channels in the heart. These channels, which transport positively charged atoms (ions) into and out of cardiac muscle cells, play critical roles in maintaining the heart's normal rhythm.
In most cases, the cause of Wolff-Parkinson-White syndrome is unknown.
Read more about the PRKAG2 gene.
Most cases of Wolff-Parkinson-White syndrome occur in people with no apparent family history of the condition. These cases are described as sporadic and are not inherited.
Familial Wolff-Parkinson-White syndrome accounts for only a small percentage of all cases of this condition. The familial form of the disorder typically has an autosomal dominant pattern of inheritance, which means one copy of the altered gene in each cell is sufficient to cause the condition. In most cases, a person with familial Wolff-Parkinson-White syndrome has inherited the condition from an affected parent.
Where can I find information about diagnosis, management, or treatment of Wolff-Parkinson-White syndrome?
These resources address the diagnosis or management of Wolff-Parkinson-White syndrome and may include treatment providers.
- Gene Tests: Familial Hypertrophic Cardiomyopathy with Wolff-Parkinson-White Syndrome, PRKAG2-Related
- Gene Tests: Wolff-Parkinson-White Syndrome
- Genetic Alliance
- MedlinePlus Encyclopedia: Wolff-Parkinson-White syndrome
You might also find information on the diagnosis or management of Wolff-Parkinson-White syndrome in Educational resources and Patient support.
To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.
You may find the following resources about Wolff-Parkinson-White syndrome helpful. These materials are written for the general public.
- MedlinePlus - Health information (3 links)
- Genetic and Rare Diseases Information Center
- Information about genetic conditions and rare diseases - Educational resources - Information pages (6 links)
- Patient support - For patients and families (5 links)
You may also be interested in these resources, which are designed for healthcare professionals and researchers.
- Gene Tests - DNA tests ordered by healthcare professionals (2 links)
- ClinicalTrials.gov
- Linking patients to medical research - PubMed
- Recent literature - OMIM - Genetic disorder catalog (2 links)
- Ventricular pre-excitation with arrhythmia
- WPW Syndrome
For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines and How are genetic conditions and genes named? in the Handbook.
Where can I find general information about genetic conditions?
The Handbook provides basic information about genetics in clear language.
- What does it mean if a disorder seems to run in my family?
- What are the different ways in which a genetic condition can be inherited?
- If a genetic disorder runs in my family, what are the chances that my children will have the condition?
- Why are some genetic conditions more common in particular ethnic groups?
These links provide additional genetics resources that may be useful.
arrhythmia ; atom ; atrial ; atrial fibrillation ; atrioventricular node ; atrium ; autosomal ; autosomal dominant ; AV node ; cardiac ; cardiac arrest ; cardiomyopathy ; cell ; channel ; complication ; Ebstein anomaly ; enzyme ; fainting ; familial ; family history ; fibrillation ; gene ; glycogen ; hypertrophic ; inheritance ; ions ; kinase ; mutation ; palpitations ; pattern of inheritance ; population ; protein ; sclerosis ; sporadic ; supraventricular ; symptom ; syncope ; syndrome ; tachycardia ; tricuspid valve ; tumor ; ventricle
Syndrome:
1.Short PR interval: less than 0.12 seconds with a normal p-wave.
2.Abnormally wide QRS (equal to or greater then 0.11 seconds)
3.Presence of a delta wave (slurring of the QRS complex) When impulses travel down the accessory pathway in an anterograde manner, ventricular preexcitation results. This produces a short PR interval and a delta wave as seen in Wolff-Parkinson-White (WPW) syndrome (see Image 9) (Wolff, 1930).
4.Secondary ST segment and T-wave changes.
The delta wave: Slow conduction through the bypass tract and more rapid conduction through the Purkinje system. When the delta wave is negative, this simulates a Q-wave. This is known as a pseudo-infarction pattern, and is seen n up to 70% of patients with WPW.
ST and T-wave changes: abnormal depolarization results in abnormal repolarization patterns.
Significance: The WPW pattern is seen in approximately 0.20 percent of the general population. Paroxysmal tachycardias occur in approximately 13 percent of healthy individuals with WPW, however much higher incidences of tachycardia are seen in hospitalized or "cardiac" patients.
The primary dysrhythmia in WPW is PSVT. The heart rate is usually 140-250 and the delta wave is not typically seen.
Atrial fibrillation and flutter is less common (20-35%) and commonly results in a pattern of wide QRS complexes. The ventricular rate may be as fast as 220-360 beats/minute. Due to the requisite short, fast refractory period these patients are a high risk for ventricular fibrillation.
"False VT," wide aberrant tachycardia may be seen in WPW in the setting of atrial fibrillation or flutter.
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