To rely solely on clinical symptoms of recurrent palpitations to evaluate the success of interventional procedures can be misleading. This study was designed to assess the efficacy of event recording in evaluating long-term success in patients treated for atrioventricular nodal reentrant tachycardia (AVNRT) or right posteroseptally located accessory pathways (RPS) either by radiofrequency (RF) or by cryoablation (CA).Methods and results
Sixty-three patients with AVNRT and eight with RPS were randomized. Patients were encouraged to activate an event recorder in the case of recurrent palpitations for the first 3 months. One year after the procedure, patients were asked specific arrhythmia related questions. Thirty-six patients underwent RF and 35 CA. Acute success was finally achieved in 34 (94%) patients in the RF and 33 (94%) in the CA groups. Assessment of long-term success demonstrated a similar proportion of palpitations in the RF and CA groups: 11 (31%) vs. 17 (49%). Only 12 patients activated the event recorder, four patients in RF, including one patient with chest pain, and eight in the CA group. Analysis of recordings revealed recurrent AVNRT or circus movement tachycardia in four patients (one RF and three CA), atrial fibrillation in one RF patient, and sinus tachycardia in six (one RF and five with CA). In addition, a complete 12 lead ECG of a recurrent arrhythmia was made in three RF and two CA patients (in-hospital or after the event recording). A total of seven patients underwent a second procedure (four RF and three CA). Without the event recorder, seven patients would have been misclassified as having recurrent arrhythmia.Conclusion
Event recording enhances the sensitivity of detecting arrhythmia recurrences in evaluating therapy efficacy and should be considered in every interventional follow-up study. Analysis of recordings showed that CA is as effective as RF in the treatment of AVNRT and RPS at long-term follow-up.