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Overview

Wolff-Parkinson-White syndrome (WPW) is a syndrome of pre-excitation of the ventricles of the heart due to an accessory pathway known as the Bundle of Kent. The diagnosis is made when a patient with pre-existing WPW patern in the ECG developes an arrythmia which involves an accesory pathway. The treatment is focused on recovering sinus rythm. Atrial Fibrillation in a patient with WPW is lifethretening and should be managed urgently.

Causes

Life Threatening Causes

Life-threatening causes include conditions which result in death or permanent disability within 24 hours if left untreated. Wolff-Parkinson-White syndrome can be a life-threatening condition and must be treated as such irrespective of the underlying cause.

Common Causes

WPW is a congenic disease

Diagnosis

Shown below is an algorithm summarizing the initial aproach to Wolff-Parkinson-White syndrome according to the 2003 ACC/AHA/ESC guidelines for the management of patients with supraventricular arrhythmias.

AVRT: AV reentrant tachycardia

Characterize the symptoms: ❑ Asymptomatic ❑ Palpitations ❑ Dyspnea ❑ Fatigue ❑ Chest discomfort ❑ Lightheadedness ❑ Syncope ❑ Polyuria Characterize the timing of the symptoms: ❑ Onset ❑ Duration ❑ Frequency

Identify possible triggers: ❑ Infection ❑ Caffeine ❑ Alcohol ❑ Nicotine ❑ Congenital heart disease ❑ Congestive heart failure ❑ Valvular disease ❑ Hypovolemia ❑ Acidosis ❑ Hyperthyroidism ❑ Hypoxia ❑ Anxiety ❑ Hypokalemia ❑ Hyperkalemia ❑ Hypoglycemia ❑ Hypothermia ❑ Toxins ❑ Stress ❑ Pulmonary embolism ❑ Coronary thrombosis ❑ Trauma

❑ Examine the patient ❑ Monitor the blood pressure ❑ Monitor the heart rate ❑ Order and monitor the ECG ❑ Assess and support ABC ❑ Give oxygen if needed ❑ Treat reversible causes if identified

Orthodromic AVRT The impulse travels from the atrium to the ventricle through the AV node and returns to the atrium through the accesory pathway. 90-95% of WPW ❑ Narrow QRS complexes ❑ Ventricular rate between 150-250 bpm (or more) usually regular ❑ Short PR interval less than one half of the tachycardia RR interval

Antidromic AVRT The impulse travels from the atrium to the ventricle through theaccesory pathway and from the ventricle to the atrium through the AV node. Less than 10% of WPW ❑ Wide QRS complexes ❑ Ventricular rate between 150-250 bpm (or more) usually regular ❑ Short PR interval more than one half of the tachycardia RR interval

Managment

Initial Management

Shown below is an algorithm summarizing the initial aproach to Wolff-Parkinson-White syndrome according to the 2003 ACC/AHA/ESC guidelines for the management of patients with supraventricular arrhythmias.

❑ Determine blood pressure ❑ Determine heart rate

Stable patient

Unstable patient

❑ Assess the ECG

❑ Urgent electrical cardioversion

Orthodromic AVRT

Antidromic AVRT

Treatment. ❑ Use Valsalva maneuvers If not effective initiate IV AV nodal blocking agent ❑ Administer Adenosine If not effective ❑ Administer Verapamil If not effective ❑ Administer Procainamide

Treatment. ❑ Administration of Procainamide, Flecainide or Ibutilide is the prefered treatment ❑ Adenosine should be used with caution because may produce AF

Wolff-Parkinson-White syndrome with Atrial fibrillation

Shown below is an algorithm summarizing the managment of Wolff-Parkinson-White syndromewith Atrial fibrillation according to the ACC/AHA/ESC 2006 Guidelines for the Management of Patients with Atrial Fibrillation.

❑ Control ventricular response ❑ If possible: terminate AF ❑ If possible: catheter ablation of the accesory pathway (class I, level of evidence B)

Stable patient

Unstable patient

❑ Restore sinus rythm (class I, level of evidence C) ❑ Ibutilide (class I, level of evidence C) ❑ Procainamide (class I, level of evidence C) ❑ Quinidine (class IIb, level of evidence B) ❑ Disopyramide (class IIb, level of evidence B) ❑ Amiodarone (class IIb, level of evidence B) ❑ Avoid AV blocking agents (class III, level of evidence B)

❑ Urgent electric cardioversion (class I, level of evidence B) ❑ Is reasonable to use Flecainide or electrical cardioversion for very rapid ventricular response (class IIa, level of evidence B)

References

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