Snapshot A 10-year-old boy presents to the pediatrician’s office for an electrocardiogram. His family history includes Wolff-Parkinson-White syndrome and sudden cardiac death. His parents are adamant about an electrocardiogram at this visit. Results show a widened QRS, a delta wave, and a shortened PR interval, confirming the diagnosis. Introduction Clinical definition a ventricular pre-excitation syndrome resulting in an aberrant conduction tract that bypasses the atrioventricular (AV) node Epidemiology risk factors family history Etiology can be familial Pathogenesis ventricular pre-excitation results from an aberrant conduction tract from the atria to the ventricle, known as the bundle of Kent this fast accessory tract bypasses the AV node ventricles then depolarize earlier than normal this causes the classic delta wave and widened QRS administration of calcium channel blockers or digoxin will worsen a supraventricular tachycardia (SVT) caused by WPW syndrome these medications block conduction in the AV node and will force more conduction down the aberrant tract, worsening WPW syndrome Associated conditions Ebstein anomaly hypertrophic cardiomyopathy Prognosis can present with atrioventricular reentrant tachycardia (AVRT) login to view 4 more bullets atrial fibrillation atrial flutter ventricular tachycardia ventricular fibrillation and sudden death Presentation Symptoms can be asymptomatic if symptomatic, patients will present with palpitations lightheadedness syncope dizziness chest pain Physical exam tachycardia Studies Electrocardiogram (ECG) delta wave short PR interval widened QRS complex may have supraventricular tachycardia if symptomatic Making the diagnosis based on clinical presentation and ECG Differential Bundle branch block distinguishing factor widened and abnormal terminal portion of QRS portion on ECG Treatment Management approach drugs that delay AV node conduction is typically contraindicated in these patients unless patients have confirmed orthodromic AVRT Medical procainamide indications login to view 2 more bullets adenosine or calcium channel blocker indication login to view 1 more bullet Non-operative electrical cardioversion indication login to view 1 more bullet radiofrequency catheter ablation indication login to view 1 more bullet Complications Sudden cardiac death