Determination of the preexcitation focus in the W-P-W picture by isopotential body-surface mapping.

Experiences with the determination of the preexcitation focus in 13 patients with W-P-W syndrome aged 18-62 years are presented. The data of ECG mapping from the chest surface and the abdominal wall were processed by computer. For classification of the maps the criteria elaborated by Yamada et al., da Ambroggi et al., and Benson et al. were used. It was possible to determine on their basis the preexcitation focus in all examined subjects, although a reduced system of ECG leads was employed. Surface ECG mapping makes possible a more precise location of the preexcitation, which is of great clinical importance for the indication of surgical treatment, determination of prognosis and of working ability.