Wolff–Parkinson–White syndrome (WPW) is one of several disorders of the electrical system of the heart that are commonly referred to as pre-excitation syndromes.
WPW is caused by the presence of an abnormal accessory electrical conduction pathway between the atria and the ventricles. Electrical signals traveling down this abnormal pathway (known as the bundle of Kent) may stimulate the ventricles to contract prematurely, resulting in a unique type of supraventricular tachycardia referred to as an atrioventricular reciprocating tachycardia.
WPW ECG Examples: