HWN Suggests

Wolff-Parkinson-White Syndrome – Part 2

Atrial fibrillation in the setting of Wolff-Parkinson-White syndrome can be quite dangerous! This is an occasion where giving the wrong drugs (i.e., adenosine or a calcium channel blocker) can be a big mistake! For reasons that are not completely clear these drugs are believed to “facilitate conduction across the accessory pathway”.

The ECG in AF/WPW is quite unique. It shows an irregular, polymorphic tachycardia without turning of the points. That’s how it can be distinguished from polymorphic VT or torsades de pointes. Procainamide or ibutilide may be the only appropriate medications for these patients. Hemodynamically unstable patients should receive synchronized electrical cardioversion.

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  Back to Basics: Wolff-Parkinson-White (WPW)

Narrow complex: Treat similar to SVT Wide complex: treat with procainamide or cardioversion.

 Afib with WPW

Treatment: · DO NOT give: adenosine, verapamil, diltiazem, digoxin, beta blocker or amio. Due to the presence of accessory pathway blocking down the AV node, may cause the accessory pathway to become the primary driver of conduction. · Treated with IV procainamide if clinically stable. Dose is 15-16 mg/kg given at a rate no faster than 50 mg/min. · If unstable: Immediate DC cardioversion

 Why rapid recognition, treatment of Wolff-Parkinson-White syndrome is important

Wolff-Parkinson-White syndrome is a relatively uncommon congenital heart defect. A large percentage of WPW patients will present a tachyarrythmia. Of this subgroup of patients, 20 percent will have atrial fibrillation. Atrial fibrillation in WPW is particularly dangerous because the normal rate-limiting function of the AV node is bypassed with an accessory tract.

Articles of Interest

AFib in Wolff-Parkinson-White Syndrome

Treatment with AV nodal blocking drugs e.g. adenosine, calcium-channel blockers, beta-blockers may increase conduction via the accessory pathway with a resultant increase in ventricular rate and possible degeneration into VT or VF.

Atrial Fibrillation in WPW Syndrome – Pearls and Pitfalls

AF in WPW – it looks similar to polymorphic VT but lacks the undulating baseline seen in torsades de pointes.

ECG Pointers: Syncope and Wolff-Parkinson-White

Cardiac Rhythms associated with WPW: Sinus Rhythm, Reentrant Paroxysmal SVT (80% of arrhythmias in WPW), Antidromic AVRT: Impulses travel anterograde down the AP and retrograde through the AV node. Rare, occurs in less than 5% of patients with WPW, Atrial fibrillation with WPW (a subset of orthodromic AVRT): 20% to 30% of patients with WPW will also have atrial fibrillation.

Hide and Seek: Intermittent Preexcitation Wolff-Parkinson-White Syndrome Case Report and Management Overview

A myriad of other tachyarrhythmias may occur in WPW syndrome. Far less common than orthodromic AVRT, antidromic AVRT may also occur at an incidence of 5% of WPW patients. Procainamide, a class 1A antiarrhythmic medication that acts by inhibiting cardiac myocyte sodium channels, is an appropriate medical treatment option in otherwise stable antidromic AVRT patients, though electrical cardioversion stands as another reasonable treatment option. Rarely, WPW may lead to sudden cardiac death (SCD) due to atrial fibrillation and subsequent ventricular tachycardia and ventricular fibrillation,

Irregular Wide Complex Tachycardia: VTach?

The differential diagnosis of irregularly irregular WCT is essentially limited to three main dysrhythmias. Dr. Littmann calls these FBI: Fast, Broad, and Irregular: Afib with LBBB Afib with RBBB Afib with WPW

Pediatric WPW

EKG shows a wide complex tachycardia rhythm. If team gives AV nodal blocking agents, the pt will devolve into a VF rhythm, and the pt will become nonresponsive. If team administers procainamide, pt will go into a rate controlled rhythm that reveals WPW and should then be placed on a procainamide drip.

Safe practice in SVT with WPW

Orthodromic SVT in WPW can be treated much like any other SVT (adenosine, vagal manoeuvres etc), whereas in antidromic SVT many of the usual drugs are contraindicated. AF is disturbingly common in WPW- 10 to 30% of patients will have it at some point.

Sirens to Scrubs: Wolff-Parkinson-White Syndrome

As you begin to coach her through vagal maneuvers and reach for your adenosine she advises you ‘I have something called Wolff-Parkinson-White – does that change anything?’ You think maybe it does, but you’re not sure...

Tachydysrhythmias with Amal Mattu and Paul Dorion

Atrial fibrillation with Wolff Parkinson White (WPW) Irregularly irregular tachycardia Changing QRS morphologies (as opposed to AF with a bundle branch block, which will be monomorphic) Rate 250-300 bpm

Treating WPW Syndrome

Wide complex tachycardia in WPW must be treated with procainamide or electrical cardioversion and AV nodal blockade avoided. This is because the pathway is probably going retrograde through the AV node (antidromic rhythm creates wide complex) and blocking the AV node could send the pathway to a completely unchecked alternative route around it.

Wolff-Parkinson Wait!

It is imperative to recognize AF with WPW, as incorrect treatment with AV nodal blocking agents can be fatal. Blocking the AV node in these patients will result in preferential use of the accessory pathway. Rates may exceed 300 or 400 bpm and are at extreme risk for degeneration into ventricular fibrillation (VF).