An interesting case of Wolff-Parkinson-White syndrome with pre-excited atrial fibrillation

Abstract

Background: Atrial fibrillation with accessory pathway can present with confounding ECG findings leading to inaccurate diagnosis sometimes leading to fatal outcomes. Treatment with AV nodal blockers is contra-indicated in pre-excited atrial fibrillation as it can lead to fatal ventricular arrythmia. Case Presentation: A 72-year-old female presenting with acute onset palpitations, chest discomfort, shortness of breath and light-headedness with similar past episodes was initially diagnosed to have atrial fibrillation. An ECG after metoprolol administration revealed the features of pre-excitation and Wolff-Parkinson-White syndrome. A repeat episode of tachyarrhythmia was terminated with electrical cardioversion and patient was followed-up in cardiology for radiofrequency ablation. Conclusion: A bizarre ECG with irregular wide complex tachycardia with QRS of varied shape and amplitude and sustained rates surpassing 200 beats per minute, suspicion of WPW syndrome with pre-excited AF should be considered. It is difficult to distinguish from polymorphic ventricular tachycardia, although electrical cardioversion is the primary therapy when hemodynamically unstable.