Snapshot A 25-year-old male presents to the emergency department complaining of palpitations. He feels anxious, lightheaded, and short of breath. Current EKG reveals a narrow-complex supraventricular tachycardia. Looking back at his medical records, you find a baseline EKG from a prior visit when he had arrived at the ED just following resolution of his symptoms. Baseline EKG is significant for a short PR interval and a wide QRS complex with an initial slurring, or delta wave. Introduction Introduction aka ventricular preexcitation syndrome, a form of atrioventricular reciprocating tachycardia (AVRT) congenital syndrome with additional conduction bundle between atrium and ventricle can bypass AV node one type is called the Bundle of Kent part of the ventricular muscle is excited prior to the regular conduction pathway because it is not slowed in the AV node Presentation and Evaluation Symptoms often asymptomatic though may lead to aberrant reentry current may progress to supraventricular tachycardia resulting in palpitations, anxiety, lightheadedness, chest pain, dyspnea syncope is uncommon Physical exam may see prominent jugular venous puslations (cannon a-waves) during SVT due to atrial contraction against the closed tricuspid valve characteristic delta wave on EKG due to slurred upstroke of Q-wave as result of partial depolarization prior to normal conduction depolarization Treatment Management of SVT in WPW unstable vitals synchronized cardioversion stable vitals procainamide safe for wide-complex/antidromic AVRT or if unsure definitive therapy radiofrequency catheter ablation ablation eliminates arrhythmias in up to 90% of patients contraindications drugs that delay AV node conduction (beta-blockers, CCB's, and adenosine) increase conduction through accessory pathway and exacerbate condition can use ONLY if narrow complex/orthodromic AVRT is confirmed