Experimental and Clinical Study of WPW Syndrome : Detection of preexcitation site through the use of body surface maps

The purpose of this experimental and clinical study was to evaluate the utility of body surface maps in detecting the preexcitation site of WPW syndrome. By using the electrical bypass tract, the electrocardiographic patterns of WPW syndrome were simulated by the fusion beat between pre- and normal excitation of the in situcanine ventricle. A comparison was made between the body surface and the epicardial maps of the same fusion beat. Throughout the ventricular activation serial body surface maps represented well the activation sequence on the epicardium. The following three points seem to be important for the detection of the preexcitation site of WPW syndrome through the use of body surface maps; 1) the location of the initial minimum, 2) the time of appearance of the voltage concavity (or the saddle) in the right anterior chest wall (in posterior preexcitation), 3) and in addition, the sequential changes in the pattern of positive and negative areas throughout the ventricular activation. In clinical use, body surface maps also localized well the preexcitation sites of the patients with WPW syndrome who underwent the operation.