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Atrial Fibrillation and Wolff-Parkinson-White Syndrome (WPW)

By

L. Brent Mitchell

, MD, Libin Cardiovascular Institute of Alberta, University of Calgary

Last full review/revision Jan 2021| Content last modified Jan 2021
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In Wolff-Parkinson-White syndrome, antegrade conduction occurs over an accessory pathway. If atrial fibrillation, develops this is a medical emergency as very rapid ventricular rates can develop.

In manifest Wolff-Parkinson-White (WPW) syndrome Wolff-Parkinson-White (WPW) syndrome Reentrant supraventricular tachycardias (SVT) involve reentrant pathways with a component above the bifurcation of the His bundle. Patients have sudden episodes of palpitations that begin and... read more , antegrade conduction occurs over the accessory pathway. If atrial fibrillation Atrial Fibrillation Atrial fibrillation is a rapid, irregularly irregular atrial rhythm. Symptoms include palpitations and sometimes weakness, effort intolerance, dyspnea, and presyncope. Atrial thrombi may form... read more develops, the normal rate-limiting effects of the atrioventricular (AV) node are bypassed, and the resultant excessive ventricular rates (sometimes 200 to 300 beats/minutes) may lead to ventricular fibrillation Ventricular Fibrillation (VF) Ventricular fibrillation causes uncoordinated quivering of the ventricle with no useful contractions. It causes immediate syncope and death within minutes. Treatment is with cardiopulmonary... read more Ventricular Fibrillation (VF) (see figure Atrial fibrillation in Wolff-Parkinson-White syndrome Atrial fibrillation in Wolff-Parkinson-White syndrome In Wolff-Parkinson-White syndrome, antegrade conduction occurs over an accessory pathway. If atrial fibrillation, develops this is a medical emergency as very rapid ventricular rates can develop... read more ) and sudden death. Patients with concealed WPW syndrome are not at risk because in them, antegrade conduction does not occur over the accessory connection.

Atrial fibrillation in Wolff-Parkinson-White syndrome

Ventricular response is very fast (RR intervals minimum of 160 msec). Shortly thereafter, ventricular fibrillation develops (lead II continuous rhythm strip at bottom).

Atrial fibrillation in Wolff-Parkinson-White syndrome

Treatment of Atrial Fibrillation and WPW Syndrome

  • Direct-current cardioversion

The treatment of choice for Wolff-Parkinson-White syndrome is direct-current cardioversion Direct-Current (DC) Cardioversion-Defibrillation The need for treatment of arrhythmias depends on the symptoms and the seriousness of the arrhythmia. Treatment is directed at causes. If necessary, direct antiarrhythmic therapy, including antiarrhythmic... read more . The usual rate-slowing drugs used in atrial fibrillation are not effective, and digoxin and the nondihydropyridine calcium channel blockers (eg, verapamil, diltiazem) are contraindicated because they may increase the ventricular rate and cause ventricular fibrillation. If cardioversion is impossible, drugs that prolong the refractory period of the accessory connection should be used. IV procainamide or amiodarone is preferred, but any class Ia, class Ic, or class III antiarrhythmic drug Drugs for Arrhythmias The need for treatment of arrhythmias depends on the symptoms and the seriousness of the arrhythmia. Treatment is directed at causes. If necessary, direct antiarrhythmic therapy, including antiarrhythmic... read more can be used.

Pearls & Pitfalls

  • Do not give digoxin or nondihydropyridine calcium channel blockers (eg, verapamil, diltiazem) to patients with atrial fibrillation and Wolff-Parkinson-White syndrome because these drugs may trigger ventricular fibrillation.

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