Wolf-parkinson-white syndrome presented with broad QRS complex tachycardia.

Broad QRS complex tachycardia is tachycardia with widened QRS complex more than 12 s and caused by various mechanisms, either supraventricular or ventricular. It is important to differentiate between ventricular and supraventricular because it will determine treatment and prognosis of patients. We report a case which was referred to us and first diagnosed as ventricular tachycardia but happened to be atrial fibrillation with RBBB. On ECG examination we found irregular broad complex of tachycardia, RBBB, extreme right axis and heart rate 170-180 beat/minute. Intravenous bolus of 300 mg amiodarone was administered within 30 minutes and continued with 900 mg/24 hours. During administration of amiodarone, heart rhythm was converted to sinus rhythm with short PR interval (0.09 s), left axis deviation, and positive delta wave at lead V1. The final diagnosis of wolf-parkinson-white (WPW) syndrome was then confirmed.