Is missing Q wave characteristic for Wolff-Parkinson-White Syndrome?
In Wolff-Parkinson-White syndrome, the normal Q wave is usually masked by the preexcitation action potential which produces the delta wave. Despite this, missing Q wave is not a diagnosis criteria of the syndrome, and up to 70 percent of the patients show a negative delta wave which causes differential diagnosis problems because it is confused with Q, according to Emergency Electrocardiography.


  When the delta wave is negative, this simulates a Q-wave. This is known as a pseudo-infarction pattern, and is seen in up to 70% of patients with WPW.


And this negative delta wave also helps in determining action potential origin, according to Medscape.


  A general rule is that Q waves (negative delta waves) point away from the earliest site of ventricular activation, which is typically the insertion point of the bypass tract.


No, you can't categorize PRS complexes as WPW syndrome. In fact there is no PRS complex. A classic ECG of WPW will show a shortened PR segment and a widened QRS (or RS or RSr' or however it looks) complex.