SummaryIt has been demonstrated that a prolonged PR interval is associated with an increased risk of AF. However, the impact of a prolonged PR interval on recurrence of paroxysmal atrial fi brillation (AF) after catheter ablation is not clear. A total of 112 patients with a prolonged PR interval (PR > 200 ms) (PPR group) and 112 age-and gender-matched control patients (on a 1:1 basis) with a normal PR interval (NPR group) were included in this study. AF recurrence was defi ned as the occurrence of confi rmed atrial tachyarrhythmia lasting more than 30 seconds beyond 3 months after catheter ablation in the absence of any antiarrhythmic treatment. During a mean follow-up period of 10.9 ± 5.5 months (range, 3-18 months), 61 patients (27.2%) developed recurrence of AF. The recurrence rate was higher in the PPR group than in the NPR group (33.9% versus 20.5%, respectively; P = 0.018). Cox regression analysis with adjustment for age, body mass index, valvular heart disease, left atrial diameter, and pulmonary vein isolation identifi ed only a prolonged PR interval as an independent predictor of recurrence of AF (hazard ratio, 1.81; 95% confi dence interval, 1.07-3.05; P = 0.027). Patients with a prolonged PR interval were at an increased risk of AF recurrence after catheter ablation. (Int Heart J 2014; 55: 126-130) Key words: Atrial tachyarrhythmia A trial fi brillation (AF) is a common cardiac arrhythmia in the general population 1) and is associated with increased cardiovascular morbidity and mortality.2,3) A recent post hoc analysis of a Danish multicenter randomized trial (DANPACE trial) showed that a prolonged PR interval is associated with an increased risk of AF in patients with sick sinus syndrome.4) These results are in accordance with the fi ndings of a large community-based cohort study in which a PR interval longer than 200 ms was associated with a doubled risk of later AF compared with a shorter PR interval.5) Catheter ablation has been established as an effective therapy for drug-refractory paroxysmal AF. However, there is still a risk of recurrence after ablation. Previous studies have examined some predictors of AF recurrence. 6,7) However, there is little information available about the impact of a prolonged PR interval on recurrence of AF after catheter ablation. In patients with a prolonged PR interval, most of the pathogenic factors for AF persist after ablation. Therefore, it is reasonable to hypothesize that a prolonged PR interval increases the risk of recurrence of AF. This retrospective study evaluated the impact of a prolonged PR interval on recurrence of AF after catheter ablation.
MethodsStudy subjects: We reviewed the records of 1593 consecutive patients with refractory symptomatic paroxysmal AF who had been prospectively entered into our database. All of these patients were referred to Beijing An Zhen Hospital, Capital Medical University for first-time circumferential pulmonary vein (PV) radiofrequency ablation from January 2008 to December 2012. The PR interval was considered to be p...