Objective: The aim of our study was to investigate the value of the transtelephonic electrocardiogram (TTECG) monitoring system during a "blanking period" of 3 months after ablation by analyzing the frequency of atrial arrhythmias episodes and the relationship between the frequency of atrial fibrillation (AF) attacks and long-term follow-up outcomes. Methods: Ninety-two patients with AT received primary ablation and were fitted with an external loop recorder for daily and symptomatic patient-triggered detection of AF recurrence during a "blanking period," which was defined as 3 months after discharge. All patients received regularly scheduled clinical follow-up programs that included 24-hour Bolter for 12 months. Atrial fibrillation recurrence was defined as an episode of AF, atrial flutter, or atrial tachycardia lasting for 30 seconds or longer, which was documented on TTECG or 24-hour Bolter. After the 12th month of monitoring, patients were divided into 2 groups based on the follow-up data: a recurrence group and a nonrecurrence group. Results: A total of 18 969 TTECGs were received, the rate of effective TTECGs was 96.1% (18 236/18 969). At the end of the blanking period, 39 (42.4%) patients with AF recurrence were recorded by TTECG monitoring, whereas 27 (29.3%) patients were recorded by electrocardiogram and 24-hour Bolter monitoring (P=.032). By analyzing the TTECG diagnosis, the percentage of total AF attacks in the recurrence group was higher than in the nonrecurrence group (median: 27.8% versus 10.6%, P < .01). The percentage of monthly AF attacks in the recurrence group occurred at a high level during the blanking period (sequent: 24.4%, 32.4%, and 28.1%; P = .65). There was also a certain amount of AF attacks in the nonrecurrence group during the blanking period, but the percentage of AF attacks in this group significantly decreased each month (sequent: 18.6%, 11.0%, and 4.9%; P < .01). Conclusion: The TTECG monitoring was superior to the standard electrocardiogram and 24-hour Holter recordings in evaluating AF recurrence after ablation. Atrial arrhythmias episodes were common during the blanking period whether the long-term follow-up outcome was a success or a failure. Atrial fibrillation attacks during the blanking period did not indicate failure of ablation in long-term outcomes. However, frequent and nonsignificantly decreasing AF attacks during the blanking period indicated a high probability of failure of AF ablation in long-term follow-up outcomes. (C) 2010 Elsevier Inc. All rights reserved.