###### Created: 2024-06-12 18:56 ###### Areas & Topics: #medicine #cardiovascular ###### Note Type: #permanent ###### Connected to: [[Adult Advanced Life Support (AALS)]] [[Peri-Arrest Rhythms]] - WPW Syndrome is a pre-excitation syndrome. - It is characterised by a congenital accessory pathway causing Atrioventricular Re-entrant Tachycardia (AVRT). - This accessory pathway is typically referred to as the 'Bundle of Kent'. - This accessory pathway can allow antegrade conduction (atria to ventricles) or retrograde conduction (ventricles to atria), creating a re-entry circuit. - Stimulation of this re-entry circuit then leads to a tachycardia. - The antegrade conduction is what allows impulses to bypass the AV node and pre-excite the ventricles. - WPW Syndrome is important to manage as if [[Atrial Fibrillation]] develops, it may be conducted to the ventricles, leading to rapid ventricular response and potentially ventricular fibrillation. ![[Image-WPW-Wolff-Parkinson-White-Syndrome-Orthodromic-Antidromic-@8x-1-1-920x1024.webp]] ### Type A and Type B - WPW Syndrome can be split into type A and type B. - Type A is where there is a left-sided accessory pathway. - Type B is where there is a right-sided accessory pathway - Type B (a right-sided accessory pathway) is much more commonly seen in cases of WPW. - On ECG, axis deviation will be opposite to the location of the accessory pathway. - Additionally, in type A there will be a dominant R wave in V1, whereas this will not be the case in type B. ### ECG - Short PR Interval (due to there being no AV conduction delay from the accessory pathway) - Delta Wave (early slowed upstroke in the QRS complex due to pre-excitation of the ventricles) - Axis deviation (left-sided deviation if type B and right-sided deviation if type A) N.B. the remaining part of the QRS complex following the delta wave will be normal as normal conduction via the AV node and other circuitry will eventually catch-up with the pre-excited impulse. ![[Pasted image 20240612190747.png]] ![[ecg059b.jpg]] ECG showing short PR interval associated with a slurred upstroke (delta wave). Note the non-specific ST-T changes which are common in WPW and may be mistaken for ischaemia. The left axis deviation means that this is type B WPW, implying a right-sided pathway, as well as a non dominant R wave in V1). ### Associations WPW Syndrome is associated with conditions including: - Hypertrophic Obstructive Cardiomyopathy (HOCM) - Mitral Valve Prolapse - Ebstein's Anomaly - Thyrotoxicosis - Secundum Atrial Septal Defect ### Management - The definitive treatment for WPW Syndrome is radiofrequency ablation of the accessory pathway. - Medical therapies can include sotalol, amiodarone or flecainide (but sotalol should not be used if there is coexisting AF). ### Resources Chhabra L, Goyal A, Benham MD. Wolff-Parkinson-White Syndrome. [Updated 2023 Aug 7]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK554437/ Wolff-Parkinson-White syndrome - NHS https://www.nhs.uk/conditions/wolff-parkinson-white-syndrome/ PassMed WPW Syndrome High Yield Textbook Tachycardias - Pulsenotes https://app.pulsenotes.com/clinical/ecgs/notes/6-tachycardias