RADIOFREQUENCY ABLATION OF ACCESSORY PATHWAYS IN THE PREEXCITATION (WOLFF-PARKINSON-WHITE) SYNDROME

Various parameters relating to the radio-frequency ablation of accesso ry pathways were studied in 53 patients (27 males, 26 females: mean ag e 38.5 [14-641 years) with a history of paroxysmal tachycardia (over 1 month to 50 years), shown to be caused by an accessory pathway (Wolff -Parkinson-White syndrome). In all patients the following values were obtained: - (1) number of procedures necessary to achieve permanent bl ockage of the accessory pathway (1-4); (2) duration of each procedure (45-420 min); (3) duration of fluoroscopy (5-102 min); (4) number of n ecessary radio-frequency applications (1-48); and (5) cumulative energ y per procedure. To ablate left-lateral pathways (n = 10) required few er procedures, shorter duration per procedure, shorter fluoroscopy tim e, fewer current applications and less total energy than coagulation o f right-sided pathways (n = 10). Those various parameters were greates t for ablation of septal and paraseptal pathways (n = 9). Pathways whi ch conducted only retrogradely (n = 15) were more difficult to ablate than those with anterograde conduction (n = 38). There were two compli cations. In one case a tension pneumothorax occurred after faulty punc ture of the subclavian vein; in the other, the left ventricle was perf orated causing an acute tamponade which required pericardiocentesis wi th subsequent suture closure of the perforation. It is concluded that, in principle, all accessory pathways, regardless of their conduction potential and site, can be ablated by a radio-frequency current.