Wolff-Parkinson-White Syndrome
OVERVIEW
- pre-excitation syndrome
- additional or accessory AV pathway
- during sinus rhythm the atrial impulse will reach the ventricles via both AV node and accessory AV pathway
- accessory pathway conducts impulse faster -> pre-excitation and short PR interval
- on reaching the ventricles the pre-excitation impulse is not conducted via the conducting system -> ventricular activation is slow (delta wave and T wave abnormalities)
CLINICAL FEATURES
- palpitations
- chest pain
- SOB
- cardiogenic shock
- collapse
- VF arrest
- AF or SVT
INVESTIGATIONS
Resting ECG
- short PR (0.12s)
- T wave abnormalities
- dominant R in V1 and V2
- may have inferior q waves but not diagnostic of MI
Type A – tall R in V1, LAD (left posterior septal path) Type B – deep S in V1, LAD (right lateral or postero-septal path) Type C – tall R in V1, inferior axis – 90º (left lateral path)
Symptomatic ECG
- AV re-entrant tachycardia or AF
- AVRT: the re-entry impulse usually travels down the AV node and back up the accessory pathway (delta wave not present), occasionally the re-entry impulse may pass down the accessory pathway and up the AV node (wide QRS tachycardia + delta wave)
- AF: rapid, irregular QRS complexes with variable QRS duration -> very rapid ventricular response -> cardiogenic shock -> VF
MANAGEMENT
Acute
- unstable -> synchronised DC shock
- stable -> anti-arrhythmics (prolongation of accessory pathway: sotalol, amiodarone, flecanide, procanamide)
- drugs that shorten refractory period are contraindicated (digoxin)
- drugs that increase ventricular rate avoid (verapamil and lignocaine)
- drugs that have no effect on refractory period of accessory pathway are useless (beta-blockers)
Long-term
- radio-frequency ablation
References and Links
LITFL
- Buttner R, Burns E. Wolff-Parkinson-White syndrome. LITFL
- Cadogan M. The history of Wolff–Parkinson–White syndrome LITFL
- Cadogan M. Who’s Afraid Of The Big Bad Wolff? LITFL
- Buttner R, Burns E. VT versus SVT with aberrancy LITFL
- Burns E. Puzzling Paroxysmal Palpitations LITFL
- Young P. Wolff-Parkinson-White Syndrome Mind Map
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at The Alfred ICU, where he is Deputy Director (Education). He is a Clinical Adjunct Associate Professor at Monash University, the Lead for the Clinician Educator Incubator programme, and a CICM First Part Examiner.
He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives. He was one of the founders of the FOAM movement (Free Open-Access Medical education) has been recognised for his contributions to education with awards from ANZICS, ANZAHPE, and ACEM.
His one great achievement is being the father of three amazing children.
On Bluesky, he is @precordialthump.bsky.social and on the site that Elon has screwed up, he is @precordialthump.
| INTENSIVE | RAGE | Resuscitology | SMACC
