Implantable loop recorders: a novel method to judge patient perception of atrial fibrillation. Preliminary results from a pilot study.

Introduction: At the present time, several techniques are used or are under investigation for atrial fibrillation (AF) therapy. Nowadays, no well-defined target for such therapies has been yet completely identified. Furthermore, AF is an arrhythmia with high rates of recurrences, both symptomatic and asymptotic. Thus the measure of therapy success rates not only based on symptom perception remains a goal to be reached.
Aims of the Study: This study investigates the role of an implantable loop recorder (ILR) as an additional tool to identify initiating and perpetuating mechanisms of AF. The role of right atrial linear ablation (RALA) procedures is also investigated using the monitoring capabilities of the ILR.
Methods and Results: Nine patients (mean age 63.8 +/- 5.9) with paroxysmal AF were referred to our institution as candidates for AF ablation. All patients (pts) had in their medical history several years of AF episodes. Therefore pts were aware of AF related symptoms. Six of them were implanted with an ILR before ablation and were monitored one month before and six months after the procedure. The ILRs stored 54 patient activated events (PAE) and 124 automatically activated events (AAE). 68% of PAEs and 67% of AAEs were classified as appropriate. Most common reasons for inappropriate detections were premature atrial or ventricular contractions among PAEs and undersensing among AAEs. The arrhythmia onset was properly identified in 4 pts (44%). The average AF recurrence rate was 10.8 +/- 3.5 ep/month before ablation and 5.0 +/- 1.8 ep/month after the procedure ( p = 0.042).
Conclusion: The ILR may be a helpful tool in monitoring pts undergoing ablation. Dedicated AF detection characteristics could give additional value to the device. RALA appears as a feasible, safe and relatively effective first approach in AF therapy.