Introduction: Clinical and electrophysiological characteristics of patients with atrioventricular nodal reentrant tachycardia (AVNRT) and paroxysmal atrial fibrillation (AF) have not been studied in a large patient cohort. We aimed to define the clinical features and cardiac electrophysiological characteristics of these patients, and to examine the incidence and identify predictors of AF recurrences after elimination of AVNRT.
Methods and results: Thirty-six patients with AVNRT and documented paroxysmal AF (Group 1) and 497 patients with AVNRT alone undergoing ablation in the same period (Group 2) were studied. There were no significant differences between groups regarding clinical features, except age, which was higher in Group 1 (p<0.001). Presence of atrial vulnerability (induction of AF lasting>30 seconds) and multiple AH jumps (>or=50 ms) before ablation were significantly more prevalent in Group 1 (p<0.001, p=0.010 respectively). During follow-up of 34 +/- 11 months, AF recurred in 10 patients (28%) in Group 1, while 2 patients in Group 2 (0.4%) developed paroxysmal AF (p<0.001). Univariate predictors of AF were: left atrial diameter>40 mm (p=0.001), presence of mitral or aortic calcification (p=0.003), atrial vulnerability after ablation (p=0.015) and valvular disease (p=0.042). However, independent predictors of AF recurrences were left atrial diameter>40 mm (p=0.002) and the presence of atrial vulnerability after ablation (p=0.034).
Conclusion: In patients with both AVNRT and paroxysmal AF, the recurrence rate of AF after elimination of AVNRT is 28%. Left atrial diameter greater than 40 mm and atrial vulnerability after elimination of AVNRT are independent predictors of AF recurrences in the long term.