■ WPW with atrial flutter and accessory pathway conduction
■ Regular wide QRS complexes
■ 1:1 conduction possible
■ Rates may reach 300 bpm.
■ WPW with atrial fibrillation and accessory pathway conduction (see
Figure 1.14)
■ Irregular wide QRS complexes
■ No P waves
■ Rates often > 250 bpm
DIFFERENTIAL
Other accessory pathway syndromes include:
■ Lown-Ganong-Levine (LGL) syndrome
■ Accessory pathway = James fibers.
■ Pathway connects the atria to the His bundle.
■ →Short PR and normal QRS on resting ECG
■ Mahaim bundles
■ Connect AV node, His bundle, orbundle branches to the ventricle
■ →Normal PR with initial slurred QRS (delta wave) on resting ECG
TREATMENT
■ Narrow complex tachycardia
■ Implies conduction through the AV node → can treat similar to
AVNRT (above)
■ Wide complex rhythm
■ Treatment of choice = synchronized electrical cardioversion (50–100J).
■ Implies AV conduction through the accessory pathway
■ Avoid all AV blocking agents (may precipitate ventricular fibrillation
[VFib]).
RESUSCITATIONFIGURE 1.14. WPW with atrial fibrillation and accessory pathway conduction.
(Reproduced, with permission, from Tintinalli JE, Kelen GD, Stapczynski JS. Emergency
Medicine: A Comprehensive Study Guide, 6th ed. New York: McGraw-Hill, 2004:200.)
WPW with narrow complex
tachycardia →treatment is
similar to AVNRT (AV blocking
drugs are OK).