[The accuracy of locating the accessory pathway before and during surgery in patients with Wolff-Parkinson-White syndrome].

The accuracy of locating the accessory pathways (APs) before and during operation in the operated 32 patients with the Wolff-Parkinson-White syndrome (WPW) was reported. There were 27 cases with the single AP, in which 17 had left-lateral free-wall pathways, 6 had left-posterior free-wall pathways, 2 had posterior septal pathways, 1 had right free-wall pathway and 1 had anterior septal pathway, and 5 cases with double APs. Taking the double APs as a single apparent AP, the accuracy was 87% (20/23) by electrocardiograms (exclusive of 9 concealed WPW), 94% (30/32) by electrophysiologic studies (EPS) and 97% (31/32) by epicardial mappings (ECM). It was difficult to discover and locate the double APs. For the 10 APs of 5 cases with double APs, the accuracy was 60% (6/10) by EPS and 70% (7/10) by ECM.