Presence of septal Q waves in a patient with WPW and manifest preexcitation.

Wolff-Parkinson-White syndrome (WPW) is characteristically diagnosed by the presence of a short PR interval, a delta wave, and a wide QRS wave on the surface ECG. In the absence of these clear criteria, absent septal Q waves have been used as additional evidence suggestive of subtle preexcitation. We report a patient with WPW and manifest anteroseptal (AS) accessory pathway who had prominent septal Q waves on the surface ECG. This case highlights that physicians should be careful not to dismiss preexcitation in the presence of septal Q waves.