Wolf Parkinson White syndrome is a pre-excitation syndrome due to an accessory conduction pathway. Electrocardiography demonstrates a short PR interval, long QRS interval and delta waves in normal sinus rhythm. Atrial fibrillation with underlying Wolf Parkinson White syndrome presents with irregular wide complex tachycardia, and can cause sudden cardiac death by precipitating ventricular fibrillation. Irregular wide complex tachycardia may be the first presentation of this underlying conduction abnormality in young patients. Emergency management for irregular wide complex tachycardia in hemodynamically unstable patients involves synchronized cardioversion, while intra-venous Procainamide can be used in hemodynamically stable patients. AV nodal blocking agents should be avoided. Treatment of choice for WPW syndrome is radiofrequency ablation.