This 35-year-old machine operator started complaining one year ago of episodes of rapid “thumping” in his precordium every 2-3 months lasting 10-20 minutes:

• Sinus rhythm with sinus arrhythmia
• Wolff-Parkinson-White (WPW)
• Anteroseptal Accessory pathway

Comment: An anteroseptal bypass tract was identified by EP studies.