Catheter Ablation of Atypical Atrioventricular Nodal Reentrant Tachycardia
Background—Due to its low prevalence, data on atypical atrioventricular nodal reentrant tachycardia (AVNRT) are scarce, and the optimal ablation method is not established. Our study aimed at assessing the efficacy and safety of conventional slow pathway ablation, as applied for typical cases, in atypical AVNRT.
Methods—We studied 2079 patients with AVNRT subjected to slow pathway ablation. In 113 patients, mean age 48.5±18.1 years, 68 female, atypical AVNRT or co-existent atypical and typical AVNRT without other concomitant arrhythmia was diagnosed. Ablation data and outcomes were compared to a group of age- and sex-matched control patients with typical AVNRT.
Results—Fluoroscopy and radiofrequency current delivery times were not different in the atypical and typical groups, 20.3±12.2 vs 20.8±12.9 min (P=0.730) and 5.9±5.0 vs 5.5±4.5 min (P=0.650), respectively. Slow pathway ablation was accomplished from the right septum in 110 patients, and from the left septum in 3 patients, in the atypical group. There was no need for additional ablation lesions at other anatomical sites, and no cases of AV block were encountered. Recurrence rates of the arrhythmia were 5.6% in the atypical (6/108 patients), and 1.8% in the typical (2/111 patients) groups, in the next 3 months following ablation (P=0.167).
Conclusions—Conventional ablation at the anatomical area of the slow pathway is the therapy of choice for symptomatic AVNRT, regardless of whether the typical or atypical form is present.
- Received July 13, 2016.
- Revision received August 20, 2016.
- Accepted September 22, 2016.