WPW syndrome is caused by an abnormal band of atrial tissue connecting the atria and ventricles, bypassing the normal AV node pathway. This bypass tract can conduct electrical signals faster than normal, causing a short PR interval on ECG and sometimes leading to supraventricular tachycardia. Complications include atrial fibrillation, ventricular tachycardia, and ventricular fibrillation. Treatment involves drugs that slow conduction through the bypass tract, radiofrequency ablation to destroy the tract, or cardioversion for atrial fibrillation.

1. ‫الرحیم‬ ‫الرحمن‬ ‫هللا‬ ‫بسم‬

2. WOLFF-PARKINSON-
WHITE SYNDROME
WPW Syndrome

3. CAUSE
• Presence of an abnormal band of atrial tissue connecting the atria and
ventricles, bypassing the AV node.
• During sinus rhythm conduction takes place partly through the AV node and
partly through the bypass tract. This results in a short PR interval ( <0.12
seconds), a delta wave in the beginning of QRS complex due to activation of
ventricles via the accessory pathway, and prolonged QRS complex (>0.12
seconds) due to fusion of excitation via two pathways.
• This tract can act as a re-entry pathway and the patient may develop
supraventricular tachycardia.

4. COMPLICATIONS
• Supraventricular tachycardia
•Atrial fibrillation
•Ventricular tachycardia
•Ventricular fibrillation (VF)
•Death

5. TREATMENT
• Narrow complex tachycardia is treated in the same way as PSVT.
• For broad-complex tachycardia, isopyramide, quinidine, flecainide,
propafenone and amiodarone are useful as these drugs increase the
refractory period and reduce the conduction rate through the bypass tract.
• In selected cases radiofrequency ablation of the bypass tract can be done.
• In patients with WPW syndrome and atrial fibrillation, cardioversion is the
treatment of choice. Caution should be employed when using digitalis,
adenosine or verapamil in patients of WPW syndrome and atrial fibrillation
because increase in AV nodal refractory period produces increased
conduction through the accessory pathway which may precipitate ventricular
fibrillation.