How can you identify WPW syndrome on the ECG?

WPW syndrome (Wolf Parkinson White syndrome) is characterized on the ECG by a short PR interval, wide QRS complex and a delta wave at the beginning of the QRS complex. Delta wave is due to early excitation of the ventricles due to an accessory conduction pathway which bypasses the normal AV conduction pathway. It is called a delta wave because of the resemblance to the Greek alphabet delta.