SERIAL ELECTROPHYSIOLOGICAL STUDIES IN THE LATE OUTCOME OF RADIOFREQUENCY ABLATION FOR ACCESSORY ATRIOVENTRICULAR PATHWAY-MEDIATED TACHYARRHYTHMIAS

Assessment of radiofrequency ablation for accessory pathway-mediated tachyarrhythmias is evaluated by a variety of methods in different institutes. However, the predictive values of these methods are not known. Therefore, serial electrocar diograms (12-lead, 24-h Holter monitoring), reviews of symptoms, and electrophysiological studies (immediate, early, late) were used in this institute to evaluate and predict late outcome in 150 patients with 174 accessory pathways. Late electrophysiological study (130 ± 11 days after ablation) detected a larger proportion of patients (11.1%) with late ablation failure than immediate (1.3% or early (7.0%) electrophysiological study, or serial electrocardiograms (1.4% or reviews of symptoms (1.4%); it showed that patients with concealed accessory pathways (11.4%), energy delivered to the ventricular sites of left concealed accessory pathways (23.3%), and those without a recordable accessory pathway activation potential (14.8%) had a higher incidence of recurrent conduction, and also provided the most accurate information for predicting late outcome with higher sensitivity (100%) and predictive accuracy (100%) than other tests.It is concluded that the value of serial electrocardiograms, symptom review, immediate and early electrophysiological studies should be downgraded, and that the late electrophysiological study has a high predictive value for late outcome and helps understanding of the residual changes in accessory pathways after initially successful ablation. © 1993 The European Society of Cardiology.