SUCCESSFUL RADIOFREQUENCY ABLATION OF A TRUE PARAHISSIAN ACCESSORY PATHWAY

Radiofrequency catheter ablation seems to become a first-line therapy for patients with paroxysmal tachycardias using an accessory pathway. We report the case of a 31-year-old woman who suffer ed from drug-resi stant recurrent reciprocating tachycardia, using an uncommon accessory pathway. The 12-lead electrocardiogram in sinus rhythm showed the fol lowing characteristics: a positive delta waves in leads I, II, aVL, aV F, QRS axis = 0 degrees, R/S in lead V1 <1, and a special QRS pattern in the precordial leads (QS or Qr in V1-V3 and QRS transition > V3). A deep septal parahissian accessory pathway has been localized using cl assic endocardial mapping procedures and has been confirmed during suc cessful radiofrequency catheter ablation. Normal auriculo-ventricular conduction has been totally preserved. No complications or recurrence were observed during the follow-lip. We have reviewed the electrophysi ologic criteria to confirm this rare accessory pathway location.