WPW is a type of SVT
Wpw (wolff-parkinson-white syndrome) is a condition where the ECG is abnormal between episodes of tachycardia.
The abnormal findings on the ECG are from an extra electrical connection in the heart
that is the cause of the svt. There are other types of SVT where the ECG is completely normal between episodes of tachycardia. In those cases the cause of the SVT is not apparent.