The manifestation of atrial flutter, particularly with 1:1 conduction, is rare in patients with ventricular preexcitation secondary to Wolff-Parkinson-White Syndrome (WPW). Very few cases have been reported in the literature. We present a 40-year old male with a history of untreated WPW who presented with severe chest pain and shortness of breath. He was found to have a rapid, regular, wide complex tachycardia. He underwent successful synchronized cardioversion, in which the patient converted tonormal sinus rhythm with classic WPW waveform characteristics, including a shortened PR interval and prolonged QRS complex with a slurred upstroke. Surprisingly, a subsequent electrophysiology study revealed atrial flutter, with bystander conduction of 1:1 atrial flutter being the most likely cause of the patient’s presenting symptoms, and a posteroseptal accessory pathway consistent with the diagnosis of WPW. While considerably rarer than ventricular tachycardia or AVRT, it is nevertheless important for clinicians to consider atrial flutter with 1:1 conduction as a potential diagnosis in patients with WPW presenting with wide complex tachycardia.
Spontaneous transformation of a concealed to manifest posteroseptal accessory pathway requiring epicardial ablation
