Trends in Subcutaneous Cardiac Monitoring Technology

Figures

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  Figure 1:. A: Reveal® XT™ and Reveal® LINQ™ ICMs (both Medtronic, Minneapolis, MN, USA). The Reveal® XT™ ICM was an early-generation ICM (19 mm × 61 mm × 8 mm in size) and was implanted subcutaneously using a small incision. The Reveal® LINQ™ device is a more recent ICM iteration (7 mm × 45 mm × 4 mm in size) that is approximately 87% smaller than its predecessor. B: The Patient Assistant Model 96000, available with the Reveal® LINQ™ Cardiac Monitoring System (Medtronic, Minneapolis, MN, USA). The Patient Assistant feature of the Reveal® LINQ™ device allows patients to mark symptomatic events for further review. C: CareLink™ (Medtronic, Minneapolis, MN, USA) for remote monitoring. The CareLink™ Network is used to download patient data from Medtronic implantable cardiac devices.

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  Figure 2:. Reveal® LINQ™ insertion blade (top) and preloaded insertion tool (bottom) (both Medtronic, Minneapolis, MN, USA). Once the ICM is injected, the insertion tool is removed and discarded. ICM: insertable cardiac monitor.

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  Figure 3:. A: BioMonitor 2® (Biotronik, Berlin, Germany). B: Confirm Rx™ ICM (Abbott Laboratories, Chicago, IL, USA).

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  Figure 4:. ICM recordings from the Reveal® LINQ™ ICM (Medtronic, Minneapolis, MN, USA) in three patients. A: Normal good-quality ventricular electrogram recordings. B: Intermittent undersensing of the ventricular signals results in the device incorrectly identifying a “pause” in the patient’s rhythm. This may have been due to movement of the device in the pocket with reduced contact. C: Intermittent oversensing of “noise” resulted in incorrect detection of a tachyarrhythmia. Movement of the device in the pocket due to patient manipulation of the ICM could be responsible.