Body surface mapping for localization of accessory pathways in WPW syndrome

Although body surface mapping (BSM) has been shown to be a useful noninvasive method to estimate accessory pathway (AP) location, fine distinction between adjacent sites has not been reported. The authors used a computer model to generate new criteria in assessing BSM patterns. These criteria were then prospectively used to predict the site of successful radiofrequency energy catheter ablation in 55 patients. Criteria included the location of the peak minimum, the slope of the line connecting the peak extrema, the slope of the septal zero isopotential contour lines on the right back, and the ratio of the slope of the extrema to the slope of the septal lines. It was possible to accurately predict the site of 49/55 (89%) APs, including separating right from left posteroseptal and free wall from septal APs. Intermediate septal pathway patterns are discussed