November 29, 2010

Treatment Options for Wolff-Parkinson-White Syndrome

In 1930, Louis Wolff, Sir John Parkinson, and Paul Dudley White published a seminal article describing 11 patients who suffered from attacks of tachycardia associated with a sinus rhythm electrocardiographic (ECG) pattern of bundle branch block with a short PR interval. This was subsequently termed Wolff-Parkinson-White (WPW) syndrome, although earlier isolated case reports describing similar patients had been published.

This article is for Medical Students & Professionals
This is a Question & Answer revision article designed for medical students and professionals preparing for the PLAB, MRCP or USMLE examinations. They are based on actual questions from these examinations. You may find the Electrocardiogram (ECG) article more useful, or one of our many articles on Diseases & Conditions, Medical Syndromes, Health & Wellness or Home Remedies.
In this article:
Wolff-Parkinson-White Syndrome
MCQ clinical scenario
MCQ answer
MCQ explanation

Wolff-Parkinson-White Syndrome

In 1943, the ECG features of preexcitation were correlated with anatomic evidence for the existence of anomalous bundles of conducting tissue that bypassed all or part of the normal atrioventricular (AV) conduction system.

Two terms, distinguished by the presence or absence of arrhythmias, have been used to describe patients with AV accessory pathways:
  • The WPW pattern is applied to the patient with preexcitation manifest on an ECG in the absence of symptomatic arrhythmias.
  • WPW syndrome is applied to the patient with both preexcitation manifest on an ECG and symptomatic arrhythmias involving the accessory pathway.
Persons with either the WPW pattern or WPW syndrome can have identical findings on the surface ECG. In either situation, antegrade conduction through the accessory pathway results in earlier activation, or preexcitation, of part of the ventricles.

MCQ clinical scenario

A patient has symptomatic WPW syndrome but is refusing surgery.

The medication of choice is:

a) Subclass IB drugs alone plus an AV nodal blocker
b) Subclass IV drugs plus an AV nodal blocker
c) subclass II drugs
d) an AV nodal blocker alone
e) a membrane-active antiarrhythmic drug (class IC or III) plus an AV nodal blocker

MCQ questions & answers on medicalnotes.info

MCQ answer

The correct answer is E.
In the scenario described, a class IC or III PLUS an AV nodal blocker is best option.

MCQ explanation

The 3 main treatment modalities for WPW syndrome are drug therapy, electrical (ie, RF) ablation, and surgical ablation.

Ablation is the first-line treatment for symptomatic WPW syndrome. It has replaced surgical treatment and most drug treatment. However, drug therapy can be useful in some instances, such as in patients who refuse ablation or in patients in whom ablation fails in one or two attempts.

For patients treated longitudinally with pharmacotherapy, consideration should be given to a membrane-active antiarrhythmic drug (class IC or III) with an AV nodal blocker, rather than just an AV nodal blocker, because of the potential for extremely rapid rates during preexcited atrial fibrillation or flutter.

See also the separate Q&A articles, Forms of Wolff-Parkinson-White Syndrome and Diagnosis of Wolff-Parkinson-White Syndrome.

Reference(s)
UpToDate: Wolff-Parkinson-White syndrome: Anatomy, epidemiology, clinical manifestations, and diagnosis. Available online: https://www.uptodate.com/contents/wolff-parkinson-white-syndrome-anatomy-epidemiology-clinical-manifestations-and-diagnosis

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