This 51-year-old truck driver experienced 1-2 episodes a year of rapid palpitation since his twenties. 1 years ago he suffered from a myocardial infarction and was treated with angioplasty and stenting of his right coronary artery. He had been back to his job without symptoms:

• Sinus rhythm
• Wolff Parkinson White (left antero-lateral accessory pathway)

The family history was positive for WPW, coronary artery disease and sudden cardiac death. Catheter ablation was advised. The patient consented and underwent successful ablation of a left lateral accessory pathway. ECG 2 is recorded one day after ablation:

• Sinus rhythm
• Inferior infarction, age undetermined
• Possible anterior infarction age undetermined
• Wolff-Parkinson-White pattern is no longer present

Comments: In ECG 1 the delta wave caused by the early conduction through the left anterolateral accessory pathway masked the previous inferior infarction. Post-ablation abnormal inferior and anterior Q waves are now seen. It is well known that WPW may mimic or may hide the QRS changes of myocardial infarction.