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Continuous AF monitoring - XPECT Trial (Reveal® XT Performance Trial) shows exceptional accuracy.
Medtronic’s insertable cardiac monitor (ICM) Reveal® XT is a small leadless device which can be positioned subcutaneously in the chest area to detect various cardiac arrhythmias. This special device is equipped with a dedicated AF detection algorithm, is approved for MRI and capable of remote data access via Medtronic’s CareLink network with a battery longevity of up to 3 years.

The XPECT study has shown that Reveal® XT has an atrial fibrillation detection performance with 96.1% sensitivity and 97.4% negative predictive value compared with simultaneous Holter monitoring [1]. The device (Reveal® XT, Medtronic, Minneapolis, MN) is therefore highly accurate at either identifying or ruling out the presence of atrial fibrillation, according to the authors, led by Prof Gerhard Hindricks (University of Leipzig, Heart Center, Germany).

The group prospectively followed 247 patients implanted with the Reveal® XT model 9529 four to six weeks previously at 24 European and Canadian centers, hooking them up to a specially modified Holter monitor for 46 hours. The Holter device could store surface-ECG data as well as data from the Reveal monitor. A core laboratory identified AF and quantified AF burden from the surface ECG for comparison with the Reveal® findings.

The patients were eligible because they were considered likely to develop paroxysmal AF by meeting one of several criteria: they were scheduled for surgical or catheter AF ablation, had frequent AF by ECG or by symptoms, or had AF symptoms despite having had an attempted catheter ablation of the arrhythmia within the previous six months, according to the report.

The device's performance in the study is far better than what has been reported for Holter monitoring performed over 7 days, 30 days, or in repeated 24-hour sessions, and especially better than relying on symptoms to identify AF, according to Prof. Hindricks et al. "Thus, the technology seems to be promising to improve both the precise detection of AF and the confirmation of absence of AF during long-term follow-up, as well as accurately assessing the AF burden."

The clinical implications of a device found to provide reliable continuous monitoring for AF are significant, they write. "Continuous and precise rhythm follow-up may help uncover the true incidence and duration of both symptomatic and asymptomatic AF episodes and establish a new standard to compare the efficacy of different AF treatment strategies."
1. Hindricks G, Pokushalov E, Urban L, et al. Performance of a new leadless implantable cardiac monitor in detecting and quantifying atrial fibrillation. Results of the XPECT trial. Circ Arrhythm Electrophysiol 2010; DOI:10.1161/CIRCEP.109.877852. Available at: