Accessory pathway (AP) conduction

Abstract

Ventricular pre-excitation occurs as a result of an extranodal accessory pathway connecting the atrium with the ventricle along the AV groove. Although the baseline ECG may be normal, the common features seen are a slurring of the initial portion of the QRS complex resulting in a delta wave, a short PR interval during normal sinus rhythm, a wide QRS duration, and secondary ST and T wave changes, all of which result from a combination of eccentric accessory pathway and midline AV nodal conduction. Ventricular pre-excitation in association with a history of palpitations is named the Wolff-Parkinson-White (WPW) syndrome.