This case report is kindly provided by Michael Rosengarten from McGill and is part of the McGill Cases. These cases come from the McGill EKG World Encyclopedia.
This recording shows a positive delta waves in I and aVL, as well as V4 to V6. The pr interval is short (<120ms.) This is suggestive of a right free wall atrio-ventricular bypass tract of the W.P.W. type.