Detection of Atrial Fibrillation After Surgical Ablation: Conventional Versus Continuous Monitoring

Abstract

Background Current guidelines recommend at least 24-hour Holter monitoring at 6-month intervals to evaluate the recurrence of atrial fibrillation (AF) following surgical ablation. In this prospective multicenter study, conventional intermittent methods of AF monitoring were compared to continuous monitoring using an implantable loop recorder (ILR). Methods From 8/2011 to 1/2014, 47 patients receiving surgical treatment for AF at two institutions had an ILR placed at the time of surgery. Each atrial tachyarrhythmia (ATA) of two or more minutes was saved. Patients transmitted ILR recordings bimonthly or following any symptomatic event. Up to 27 minutes of data was stored before files were overwritten. Patients also received ECG and 24-hour Holter monitoring at 3, 6, and 12-months. ILR compliance was defined as any transmission between 0–3 months, 3–6 months, or 6–12 months. Freedom from ATAs were calculated and compared. Results ILR compliance at 12-months was 93% compared to ECG and Holter compliance of 85% and 76% respectively. ILR devices reported a total of 20,878 ATAs. Of these, 11% of episodes were available for review and 46% were confirmed as AF. Freedoms from ATAs were no different between continuous and intermittent monitoring at one year. Symptomatic events accounted for 187 episodes. However, only 10% were confirmed as AF. Conclusions ILR was equivalent at detecting ATAs compared to Holter or ECG. However, the high rate of false positives and limited number of events available for review present barriers to broad implementation of this form of monitoring. Very few symptomatic events were AF upon review.

Comparison of two modes of long-term ECG monitoring to assess the efficacy of catheter ablation for paroxysmal atrial fibrillation

“…Thus, false AF/AT detection, which was previously shown to exceed 50% (ref. 21,22 ), may remain a weak point of ILR monitoring.…”

“…19 ). Finally, monitoring with ILR has an advantage of continuous application for a much longer time 14,[20][21][22][23][24] . However; limited memory for real ECG data with storing of overwritten files as frequency histograms has been only partly solved by implementing once-a-day automatic transtelephonic data transmission specifically in asymptomatic patients who may not activate transfer of all necessary ECG recordings.…”

Evaluation of new generation loop recorders placed during surgical ablation for atrial fibrillation

“…LRs have their limitations for rhythm analysis. Damiano et al have highlighted the potential for false positive atrial tachyarrhythmia events . Their report, however, used an older‐generation LR which evaluated R‐R interval variation only whereas the LR in our study assesses both R‐R interval and P‐wave variations.…”

“…LRs may limit these visits since the devices can transmit rhythm data wirelessly for physician analysis. Significantly better compliance in monitoring with LRs compared to Holter monitors has been reported in postsurgical ablation patients . Since LRs permit data transmission from both home and in‐clinics this may result in increased detection of postoperative arrhythmias.…”

Reduction of Arrhythmia Burden and Reverse Remodeling in Patients with Persistent Atrial Fibrillation and Severe Atrial Remodeling: The Benefits of Hybrid Ablation

“…After electrogram analysis, reported accuracy of 60% and 47% has been reported in two postablation studies 10,11 and in a postsurgical maze series only 47% of AF events were adjudicated as AF. 12 Thus the AF burden detected by the device should perhaps be thought of as the upper limit, although since the device only declares episodes of at least 2 minutes duration, short AF episodes may also be missed. Having said this, although some AF detections by ILR are false, more true AF recurrences are invariably detected than by conventional intermittent recording.…”