View source for Wolff–Parkinson–White syndrome

==Background==
*Abbreviation: WPW
*Congenital pre-excitation syndrome
*Presence of an accessory electrical pathway between atria and ventricles predisposing to supraventricular tachycardia
*Associated with certain genetic predispositions, [[Ebstein anomaly]], and [[hypokalemic periodic paralysis]]<ref>https://rarediseases.org/rare-diseases/wolff-parkinson-white-syndrome/</ref> <ref>https://patient.info/doctor/wolff-parkinson-white-syndrome-pro</ref>

===Type A===
*Delta wave and QRS complex predominantly upright in precordial leads <ref>https://patient.info/doctor/wolff-parkinson-white-syndrome-pro</ref>
*Dominant R wave (greater than S amplitude) in V1 may have appearance of right bundle branch block <ref>https://emedicine.medscape.com/article/159222-workup#c8</ref>

===Type B===
*Delta wave and QRS complex predominantly negative in V! and V2
*Delta wave and QRS complex predominantly positive in other precordial leads <ref>https://patient.info/doctor/wolff-parkinson-white-syndrome-pro</ref>
*Appearance of left bundle branch block <ref>https://emedicine.medscape.com/article/159222-workup#c8</ref>

===Orthodromic Type===
*Most common variant (~95% of cases)
*Accessory pathway (Kent bundles) allows retrograde reentry conduction
*QRS narrow (delta wave absent)
**Referred to as 'concealed' accessory pathway <ref>https://emedicine.medscape.com/article/159222-workup#c8</ref>
*May see ST depression, TWI
*Rate 150-250 bpm

===Antidromic Type===
*Least common variant (~5% of cases)
*Accessory pathway used for anterograde conduction
*QRS wide, delta wave present
*Rate 160-220 bpm, regular

===Atrial Fibrillation and Flutter<ref>Burns E. Wolff-Parkinson-White Syndromes. Life in the Fast Lane. http://lifeinthefastlane.com/ecg-library/pre-excitation-syndromes/.</ref>===
*[[Atrial fibrillation]] in up to 20% of patients with WPW
**Irregular rhythm, wide QRS complexes
**Changing QRS complexes in shape and morphology
**Axis remains stable as opposed to polymorphic VT
*[[Atrial flutter]] in ~7% of patients with WPW
**Similar features to atrial fibrillation with WPW
**Except regular rhythm
**Easily mistaken for monomorphic ventricular tachycardia
**Note that if unclear, always safest to assume VT and treat with shock
*Treatment with AV nodal blocking agents (adenosine, beta-blockers, calcium-channel blockers, amiodarone, digoxin) may incite [[ventricular fibrillation]] or [[ventricular tachycardia]]
*"Manifest WPW" = degeneration into VT or VF

==Clinical Features==
*Suspect in any patient with ventricular rate >300
===Infants===
*Irritability, feeding intolerance
*CHF
*Intercurrent febrile illness
===Children===
*Chest pain, palpitations
*Shortness of breath
*Syncope/near-syncope
===Adults===
*Sudden onset "racing heart"

==Differential Diagnosis==
{{Palpitations DDX}}

==Evaluation==
===Workup===
*[[ECG]]

===Evaluation===
''Although the ECG and an electrophysiology study are diagnostic, the characteristic features are not always seen on ECG''
*Short PR interval - <0.12sec
**Due to loss of normal AV node conduction delay
**Differentiate from [[premature junctional complex]]
*Delta wave / slurred upstroke
**Due to early activation of ventricular myocardium
*QRS duration > 0.10 sec
**Represents a fusion beat
*Dominant R wave in V1, Type A WPW
**Left sided accessory pathway
*Dominant S wave in V1, Type B WPW
**Right sided accessory pathway
*Tall R waves in V1-V3 with [[T wave]] inversion
**Mimic RVH
*"Negative" delta waves in III and aVF
**Appear as pseudo-infarct Q waves
**Mimics prior inferior infarct

==Management==
===Orthodromic===
''Treat like paroxysmal SVT''
*Unstable
**Cardioversion (synchronized)
**Adult: 50-100 J
**Peds: 0.5-2 J/kg
*Stable
**Calcium channel blockers, beta-blockers, procainamide, or adenosine
**Procainamide safe irrespective of type of pathway conduction

===Antidromic===
''Treat like ventricular tachycardia''
*Synchronized cardioversion
**Adult: 50-100 J
**Peds: 0.5-2 J/kg
**Procainamide: 20-50mg/min IV over 30min (up to 17mg/kg, hypotension, or 50% widening of QRS complex); mainenance 1-4 mg/min
***Avoid if prolong QT or CHF
**Amiodarone with 'ABCD' drugs ie adenosine, beta-blockers, calcium-channel blockers, digoxin
*Wide-complex, irregular (presumed preexcited A-fib)
**Unsynchronized cardioversion (200J)

===Atrial Fibrillation and Atrial Flutter===
*Stable
**Procainamide 20-50 mg/min until arrhythmia suppressed
**Synchronized cardioversion, 100 - 200 J
*Unstable - synchronized cardioversion
**Consider higher joule dosage and frequency of repeats than for stable
*Avoid AV nodal blocking agents

==Disposition==
===Discharge===
*Consider if dysrhythmia was easily terminated and can arrange outpatient EP study with possible RF catheter ablation
*Consider consulting cardiologist regarding outpatient [[beta-blockers]] vs. more potent medications ([[amiodarone]], [[sotalol]], [[flecainide]], etc.)

===Admit<ref>Ellis CR et al. Wolff-Parkinson-White Syndrome Treatment & Management. eMedicine. Dec 4, 2015. http://emedicine.medscape.com/article/159222-treatment#showall.</ref>===
*Patients with [[chest pain]], [[CHF]], [[electrolyte imbalance]], or required [[cardioversion]]
*[[Syncope]]
*Uncertain diagnosis (wide-complex tachycardia)
*Significant associated structural heart disease (MVP, cardiomyopathy)
*Family history of [[Sudden cardiac death]]
*[[Atrial flutter]] or [[atrial fibrillation]]

==See Also==
*[[Paroxysmal supraventricular tachycardia]]
*[[Atrial fibrillation (main)]]
*[[Atrial fibrillation with RVR]]
*[[Tachycardia (narrow)]]
*[[Tachycardia (wide)]]

==External Links==
[https://www.youtube.com/watch?time_continue=38&v=qrhWH2_KKOY WPW with AFIB]

==References==
<references/> 

[[Category:Cardiology]]