View source for Wolff-Parkinson-White syndrome overview

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{{Wolff-Parkinson-White syndrome}}
{{CMG}}; '''Associate Editor-In-Chief:'''  {{Sara.Zand}} {{CZ}}

==Overview==

[[Wolff-Parkinson-White]] ([[WPW]]) syndrome is the most common cause of [[ventricular pre-excitation]] and the second common cause of [[supraventricular tachycardia]]. There is a [[muscle fiber]] that bridges the [[atrioventricular groove]] providing electrical continuity between the atrium and ventricle in parallel to the [[atrioventricular node-His-Purkinje axis]]. The [[atrial]] impulse activates the entire or part of the [[ventricle]] or the [[ventricular impulse]] activates the entire [[atrium]] or part of it, earlier than normally be expected. Patients with [[WPW syndrome]] may present with abrupt [[palpitation]], [[presyncope]], [[syncope]], or [[ sudden cardiac death]]([[SCD]]). In some patients, [[SCD]] is the first presentation of [[WPW syndrome]], especially in the setting of [[atrial fibrillation]] with a [[rapid ventricular response]]. [[Wolff-Parkinson-White syndrome]] is named after the cardiologists [[Louis Wolff]], John Parkinson, and [[Paul Dudley White]] who gave a definitive description of the conduction disorder of the heart in 1930.  The term [[Wolff-Parkinson-White syndrome]] was coined in 1940. [[Bundle of Kent]] was first discovered by [[Albert Frank Stanley Kent]], a British physiologist following finding the lateral branch in the atrioventricular groove of the monkey heart. Wolff-Parkinson-White ([[WPW]]) syndrome is the occurrence of [[arrhythmia]] in the presence of an [[accessory pathway]]. [[WPW]] can be classified according to the site of origin, location in the [[mitral]] or [[tricuspid]] annulus, type of conduction (antegrade vs retrograde), and characteristics of the conduction (decremental vs nondecremental).  In addition, WPW can be classified based of the type of [[atrioventricular reciprocating tachycardia]] ([[AVRT]]) it causes, which can be either orthodromic (~95% of the cases) or antidromic.In normal individuals, electrical activity in the heart is initiated in the [[sinoatrial node|sinoatrial]] (SA) node (located in the [[right atrium]]), propagates to the [[atrioventricular node|atrioventricular]] (AV) node, and then through the [[bundle of His]] to the ventricles of the heart.  Individuals with [[Wolf-parkinson-White]] ([[WPW]]) have an [[accessory pathway]], known as the [[bundle of Kent]], that communicates between the [[atria]] and the [[ventricles]].  The conduction through the accessory pathway can be bidirectional (most commonly), only retrogarde (less common), or only antegrade (least common).  The most common type of tachycardia associated with WPW is [[atrioventricular reciprocating tachycardia]] ([[AVRT]]).  The accessory pathway does not share the rate-slowing properties of the [[AV node]]; therefore, the combination of an accessory pathway and cardiac [[arrhythmia]] can trigger [[ventricular fibrillation]], a leading cause of [[sudden cardiac death]]. The [[prevalence]] of [[ WPW syndrome]] is approximately 100-300 per 100000 individuals worldwide. The [[incidence]] of [[tachyarrhythmia]] was estimated to be 1000 cases per 100000 individuals in the year in patients with [[WPW ]] pattern. The [[incidence]] of [[sudden cardiac death]] in patients with [[Wolff-Parkinson-White syndrome]] was estimated to be 70-450 per 100000 patient-years. [[WPW]] syndrome is more commonly observed among young patients. In one study [[ WPW syndrome]] was observed in 7% of individuals over 60-year-old. [[Men]] are more commonly affected with [[WPW syndrome]] than [[women]]. The [[men]] to [[women]] ratio is approximately 2 to 1. There is no racial predilection for [[WPW syndrome]]. High-risk criteria for [[sudden cardiac death]] in [[Wolff-Parkinson-White syndrome]] during electrophysiology study include the presence of multiple [[accessory pathways]], [[R-R interval]] <250 milliseconds in antegrade conduction of [[accessory pathway]] during inducing [[atrial fibrillation]], sustained [[atrial fibrillation]] induced by [[AV re-entry tachycardia]], presence of [[Structural heart disease]] such as [[ebstein anomaly]] or [[hypertrophic cardiomyopathy]].Patients with [[WPW]] pattern can remain asymptomatic through all their lives, nearly 65% of adolescents and 40% of adults present [[ECG]] changes but remain asymptomatic. Complications Wolff-Parkinson-White syndrome is a consequence of symptomatic [[tachycardias]] and can occur at any age. Common complications of tachyarrhythmia associated [[WPW]] disease include reduced [[blood pressure]] and [[syncope]], [[tachycaria]] induced [[cardiomyopathy]], [[cardiac arrest]], [[ventricular fibrillation]], [[usdden cardiac death]], complications of [[ablation]], side effects of [[medications]]. [[SCD]] may occur in [[WPW]] syndrome due to rapid conduction of [[atrial fibrillation]] with [[heart rate]] >240/min to the ventricles via the accessory bypass tract leading [[ventricular fibrillation]]. Prognosis is generally excellent in asymptomatic [[WPW]] pattern. [[Catheter ablation]] ([[radiofrequency ablation]]) has a success rate between 95 - 98%, which varies depending on the location and number of [[accessory pathways]]. Successful ablation prevents future [[supraventricular tachyarrhythmia]]. The risk of lethal arrhythmia in asymptomatic children is higher than in adults. Long-term rates of [[atrial fibrillation]] in [[adult]] patients that present with [[WPW ]] remains high despite [[ablation]]. Increased risk of [[atrial fibrillation]] in ablated [[WPW]] patients may be related [[atrial fibrillation]] genesis. The diagnose of [[WPW]] pattern is commonly made by an incidental [[electrocardiogram|ECG]] finding in an [[asymptomatic]] individuals. The characteristic [[EKG]] finding is a [[delta wave]], which represents the pre-excitation of the [[ventricles]] through the [[accessory pathway]]. This phenomenon presents because the [[AV node]] has the property of slowing the impulses, therefore the conduction through the [[accessory pathway]] is faster, therefore the [[ventricles]] are excited through two different pathways. The [[delta wave]] is an upstroke in the [[R wave]] of the [[QRS]] complex that is associated with a short [[PR interval]]. [[Delta waves]] are only present when the patient is in sinus rhythm, when[[ tachycardia]] starts the [[delta wave]] is no longer present. Patients [[WPW]] syndrome with episodes of [[atrial fibrillation]] will present [[ECG ]] with rapid irregular [[wide-complex tachycardia]].  The combination of [[atrial fibrillation]] and [[WPW]] may increase the risk of very rapid [[antidromic AVRT]] and occurrence of [[ventricular fibrillation]]. [[AV node]] blocking agents are contraindicated in these patients because it will enhance the conduction through the [[accessory pathway]]. Patients with [[WPW]] may exhibit more than one [[accessory pathway]] which is common in patients with [[Ebstein's anomaly]]. The most common combination of accessory pathways in [[Ebstein]] anomaly was the right posteroseptal and right free wall pathway. [[Wolff-Parkinson-White syndrome]] is sometimes associated with [[Leber's hereditary optic neuropathy]] (LHON), a form of [[mitochondrial disease]]. Symptoms of [[WPW syndrome]] may include [[Palpitation]], [[Chest pain]] or [[chest tightness]], [[Dizziness]], [[Light-headedness]], Brief [[loss of consciousness]], [[Shortness of breath]], [[Exercise intolerance]], [[Anxiety]]. The most common [[arrhythmias]] associated with Wolff-Parkinson-White syndrome is [[AV reentry tachycardia]]. [[WPW syndrome]], uncommonly presents as [[cardiac arrest]] or [[sudden cardiac death]].The accessory pathway of [[WPW syndrome]] is present since birth.  The age of presentation of [[tachyarrhythmia]] varies from patient to patient. [[Infants]] may develop [[heart failure]] if not treated immediately. Symptoms of tachycardia related  [[WPW syndrome]] in [[infants]] may include [[Lethargy]], [[Breathlessness]], [[Loss of appetite]]. [[Wolff-Parkinson-White]] ([[WPW]]) pattern is characterized by  [[ECG]] findings such as a short [[PR interval]] and a [[delta wave]] and wide [[QRS]] complex. [[ WPW syndrome]] is the occurrence of [[tachycardia]] with or without associated symptoms in a subject with existing [[WPW]] pattern. [[WPW syndrome]] can present as an orthodromic or antidromic [[AVRT]] during which the [[delta wave]] no longer appears.  [[Atrial fibrillation]] in a patient with [[WPW]] should be suspected when there is [[ECG]] findings of an irregularly irregular [[rhythm]] and absent [[P wave]]s suggestive of [[atrial fibrillation]] in the context of a [[heart rate]] higher than 240 beats per minute. .The electrophysiologic study is used for determining the location and number of [[accessory pathways]], determining the mechanism of [[tachycardia]], establishing the diagnosis in those patients with questionable resting [[EKG]]. Treatment is based on the risk stratification of the individual.  Risk stratification is performed to determine which individuals with [[WPW syndrome]] are at risk for [[sudden cardiac death]] (SCD). [[Sudden cardiac death]] in these individuals is due to the propagation of an [[atrial arrhythmia]] to the [[ventricles]] at a very high rate. Noninvasive tests have a 70% [[positive predictive value]] and 30% [[negative predictive value]] for identifying [[pathways]] with [[life-threatening]] properties.[[ Electrophysiologic studies]] are useful for evaluation of patients' [[symptoms]]. [[Wolff-Parkinson-White syndrome]] patients who are hemodynamically unstable, as reflected by the presence of [[hypotension]], [[cold extremities]], [[mottling]] or [[peripheral cyanosis]], or those who present with ischemic [[chest pain]] or decompensated [[heart failure]] must undergo [[cardioversion]] urgently.



==Historical Perspective==
[[Wolff-Parkinson-White syndrome]] is named after the cardiologists [[Louis Wolff]], John Parkinson, and [[Paul Dudley White]] who gave a definitive description of the conduction disorder of the heart in 1930.  The term [[Wolff-Parkinson-White syndrome]] was coined in 1940. [[Bundle of Kent]] was first discovered by [[Albert Frank Stanley Kent]], a British physiologist following finding the lateral branch in the atrioventricular groove of the monkey [[heart]]. 

==Classification==
[[Wolff-Parkinson-White]] ([[WPW]]) syndrome is the occurrence of [[arrhythmia]] in the presence of an [[accessory pathway]].  [[WPW]] can be classified according to the site of origin, location in the [[mitral]] or [[tricuspid]] annulus, type of conduction (antegrade vs retrograde), and characteristics of the conduction (decremental vs nondecremental).  In addition, WPW can be classified based on the type of [[atrioventricular reciprocating tachycardia]] ([[AVRT]]) it causes, which can be either orthodromic (~95% of the cases) or antidromic.
==Pathophysiology==
In normal individuals, electrical activity in the heart is initiated in the [[sinoatrial node|sinoatrial]] (SA) node (located in the [[right atrium]]), propagates to the [[atrioventricular node|atrioventricular]] (AV) node, and then through the [[bundle of His]] to the ventricles of the heart.  Individuals with [[Wolf-parkinson-White]] ([[WPW]]) have an [[accessory pathway]], known as the [[bundle of Kent]], that communicates between the [[atria]] and the [[ventricles]].  The conduction through the accessory pathway can be bidirectional (most commonly), only retrogarde (less common), or only antegrade (least common).  The most common type of tachycardia associated with WPW is [[atrioventricular reciprocating tachycardia]] ([[AVRT]]).  The accessory pathway does not share the rate-slowing properties of the [[AV node]]; therefore, the combination of an accessory pathway and cardiac [[arrhythmia]] can trigger [[ventricular fibrillation]], a leading cause of [[sudden cardiac death]].

==Causes==

==Differentiating Xyz from Other Diseases==

==Epidemiology and Demographics==
The [[prevalence]] of [[ WPW syndrome]] is approximately 100-300 per 100000 individuals worldwide. The [[incidence]] of [[tachyarrhythmia]] was estimated to be 1000 cases per 100000 individuals in the year in patients with [[WPW ]] pattern. The [[incidence]] of [[sudden cardiac death]] in patients with [[Wolff-Parkinson-White syndrome]] was estimated to be 70-450 per 100000 patient-years. [[WPW]] syndrome is more commonly observed among young patients. In one study [[ WPW syndrome]] was observed in 7% of individuals over 60-year-old. [[Men]] are more commonly affected with [[WPW syndrome]] than [[women]]. The [[men]] to [[women]] ratio is approximately 2 to 1. There is no racial predilection for [[WPW syndrome]].


==Risk Factors==
High-risk criteria for [[sudden cardiac death]] in [[Wolff-Parkinson-White syndrome]] during electrophysiology study include the presence of multiple [[accessory pathways]], [[R-R interval]] <250 milliseconds in antegrade conduction of [[accessory pathway]] during inducing [[atrial fibrillation]], sustained [[atrial fibrillation]] induced by [[AV re-entry tachycardia]], precence of [[Structural heart disease]] such as [[ebstein anomaly]] or [[hypertrophic cardiomyopathy]].

==Screening==

==Natural History, Complications, and Prognosis==
Patients with [[WPW]] pattern can remain asymptomatic through all their lives, nearly 65% of adolescents and 40% of adults present [[ECG]] changes but remain asymptomatic. Complications Wolff-Parkinson-White syndrome is a consequence of symptomatic [[tachycardias]] and can occur at any age. Common complications of tachyarrhythmia associated [[WPW]] disease include reduced [[blood pressure]] and [[syncope]], [[tachycaria]] induced [[cardiomyopathy]], [[cardiac arrest]], [[ventricular fibrillation]], [[usdden cardiac death]], complications of [[ablation]], side effects of [[medications]]. [[SCD]] may occur in [[WPW]] syndrome due to rapid conduction of [[atrial fibrillation]] with [[heart rate]] >240/min to the ventricles via the accessory bypass tract leading [[ventricular fibrillation]]. Prognosis is generally excellent in asymptomatic [[WPW]] pattern.[[Catheter ablation]] ([[radiofrequency ablation]]) has a success rate between 95 - 98%, which varies depending on the location and number of [[accessory pathways]]. Successful ablation prevents future [[supraventricular tachyarrhythmia]]. The risk of lethal arrhythmia in asymptomatic children is higher than in adults. Long-term rates of [[atrial fibrillation]] in [[adult]] patients that present with [[WPW ]] remains high despite [[ablation]]. Increased risk of [[atrial fibrillation]] in ablated [[WPW]] patients may be related [[atrial fibrillation]] genesis.

==Diagnosis==
===Diagnostic Study of Choice===
The diagnose of [[WPW]] pattern is commonly made by an incidental [[electrocardiogram|ECG]] finding in an [[asymptomatic]] individuals. The characteristic [[EKG]] finding is a [[delta wave]], which represents the pre-excitation of the [[ventricles]] through the [[accessory pathway]]. This phenomenon presents because the [[AV node]] has the property of slowing the impulses, therefore the conduction through the [[accessory pathway]] is faster, therefore the [[ventricles]] are excited through two different pathways. The [[delta wave]] is an upstroke in the [[R wave]] of the [[QRS]] complex that is associated with a short [[PR interval]]. [[Delta waves]] are only present when the patient is in sinus rhythm, when[[ tachycardia]] starts the [[delta wave]] is no longer present. Patients [[WPW]] syndrome with episodes of [[atrial fibrillation]] will present [[ECG ]] with rapid irregular [[wide-complex tachycardia]].  The combination of [[atrial fibrillation]] and [[WPW]] may increase the risk of very rapid [[antidromic AVRT]] and occurrence of [[ventricular fibrillation]]. [[AV node]] blocking agents are contraindicated in these patients because it will enhance the conduction through the [[accessory pathway]]. Patients with [[WPW]] may exhibit more than one [[accessory pathway]] which is common in patients with [[Ebstein's anomaly]]. The most common combination of accessory pathways in [[Ebstein]] anomaly was the right posteroseptal and right free wall pathway. [[Wolff-Parkinson-White syndrome]] is sometimes associated with [[Leber's hereditary optic neuropathy]] (LHON), a form of [[mitochondrial disease]].
===History and Symptoms===
Symptoms of [[WPW syndrome]] may include [[Palpitation]], [[Chest pain]] or [[chest tightness]], [[Dizziness]], [[Light-headedness]], Brief [[loss of consciousness]], [[Shortness of breath]], [[Exercise intolerance]], [[Anxiety]]. The most common [[arrhythmias]] associated with Wolff-Parkinson-White syndrome is [[AV reentry tachycardia]]. [[WPW syndrome]], uncommonly presents as [[cardiac arrest]] or [[sudden cardiac death]].The accessory pathway of [[WPW syndrome]] is present since birth.  The age of presentation of [[tachyarrhythmia]] varies from patient to patient. [[Infants]] may develop [[heart failure]] if not treated immediately. Symptoms of tachycardia related  [[WPW syndrome]] in [[infants]] may include [[Lethargy]], [[Breathlessness]], [[Loss of appetite]].
===Physical Examination===

===Laboratory Findings===

===Electrocardiogram===
[[Wolff-Parkinson-White]] ([[WPW]]) pattern is characterized by  [[ECG]] findings such as a short [[PR interval]] and a [[delta wave]] and wide [[QRS]] complex.[[ WPW syndrome]] is the occurrence of [[tachycardia]] with or without associated symptoms in a subject with existing [[WPW]] pattern. [[WPW syndrome]] can present as an orthodromic or antidromic [[AVRT]] during which the [[delta wave]] no longer appears.  [[Atrial fibrillation]] in a patient with [[WPW]] should be suspected when there is [[ECG]] findings of an irregularly irregular [[rhythm]] and absent [[P wave]]s suggestive of [[atrial fibrillation]] in the context of a [[heart rate]] higher than 240 beats per minute.

===X-ray===

===Echocardiography and Ultrasound===

===CT scan===

===MRI===

===Other Imaging Findings===

===Other Diagnostic Studies===
.The electrophysiologic study is used for determining the location and number of [[accessory pathways]], determining the mechanism of [[tachycardia]], establishing the diagnosis in those patients with questionable resting [[EKG]].
==Treatment==
==Risk stratification==
Treatment is based on the risk stratification of the individual.  Risk stratification is performed to determine which individuals with [[WPW syndrome]] are at risk for [[sudden cardiac death]] ([[SCD]]). [[Sudden cardiac death]] in these individuals is due to the propagation of an [[atrial arrhythmia]] to the [[ventricles]] at a very high rate. Noninvasive tests have a 70% [[positive predictive value]] and 30% [[negative predictive value]] for identifying [[pathways]] with [[life-threatening]] properties.[[ Electrophysiologic studies]] are useful for evaluation of patients' [[symptoms]].
==Cardioversion==
[[Wolff-Parkinson-White syndrome]] patients who are hemodynamically unstable, as reflected by the presence of [[hypotension]], [[cold extremities]], [[mottling]] or [[peripheral cyanosis]], or those who present with ischemic [[chest pain]] or decompensated [[heart failure]] must undergo [[cardioversion]] urgently.

===Medical Therapy===

=== Interventions ===

===Surgery===

===Primary Prevention===

===Secondary Prevention===


[[Category:Disease]]
[[Category:Obstetrics]]
[[Category:Pregnancy]]
[[Category:Emergency medicine]]
[[Category:Cardiology]]

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