Incidence, Duration, Pattern and Burden of DeNovo Atrial Arrhythmias Detected by Continuous ECG Monitoring Using an Implantable Loop Recorder Following Ablation of the Cavotricuspid Isthmus

Abstract Background Following cavotricuspid isthmus (CTI) ablation, many patients with atrial flutter (AFL) are diagnosed with atrial fibrillation (AF). The incidence, duration, pattern, and burden of AF remain undefined. These may have implications for the management of these patients. Objective To classify the incidence, duration, pattern and burden of AF/AFL using an implantable loop recorder [ILR] after CTI ablation. Methods We enrolled consecutive patients with CTI dependent AFL, no known history of AF, and CHA2DS2-VASc ≥ 2. An ILR (Medtronic [Minneapolis, MN] LINQTM) was implanted before or within 90 days of ablation. The time to first AF/AFL, pattern, duration, and burden of longest AF/AFL were determined. Five distinct AF/AFL cohorts were identified – no AF/AFL and those with recurrences of isolated, clustered, frequent, or persistent AF/AFL. Results 52 patients (81% male; 73 ± 9 years; CHA2DS2-VASc 3.7 ± 1.2) were followed for 784 days [IQR 263, 1150]. AF/AFL occurred in 44 (85%) patients at 64 days [IQR 8,189] post-CTI ablation and was paroxysmal in 31 (70%) patients (burden 0.6% IQR [0.1, 4.8]). AF/AFL was isolated (n = 5, 11%), clustered (n =7, 16%), frequent (n =19, 43%), and persistent (n =13, 30%). The longest AF episode was Conclusion Following CTI ablation in AFL patients, although AF/AFL occurs in most patients, the burden is low and episodes were