Device clinic teamwork to identify and prevent electrical resets for implantable loop recorders

Implantable loop recorders (ILRs) are diagnostic tools used in cardiac electrophysiology (EP) to reveal conduction system disease in determining the etiology of syncope, and in the diagnosis of atrial fibrillation (AF) for treatment of cryptogenic strokes. The increased utility of these tools became apparent with the results of the CRYSTAL AF trial in 2014.1Sanna T. Diener H.C. Passman R. et al.Cryptogenic stroke and underlying atrial fibrillation.N Engl J Med. 2014; 370: 2478-2486Crossref PubMed Scopus (1430) Google Scholar It showed the ILR can detect AF episodes better than external, continuous mobile cardiac monitors after a cryptogenic stroke. Use of ILRs for syncope patients is recommended as useful in selected ambulatory patients in the 2017 ACC/AHA/HRS Guidelines for the evaluation and management of patients with syncope.2Shen W.-K. Sheldon R.S. Benditt D.G. et al.2017 Guideline for the evaluation and management of patients with syncope: a report of the American College of Cardiology / American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society.Circulation. 2017; 136: e60-e122Crossref PubMed Scopus (180) Google Scholar A combination of both syncope and AF indications may occur. In June 2021, Medtronic, Inc (Minneapolis, MN) issued an advisory for Reveal LINQs with TruRhythm (LINQ I) for partial electrical resets caused by a software defect. Exposure to electromagnetic interference such as electrocautery or cardioversions near the ILR were identified as the cause for the partial electrical reset, with no pause or bradycardia episode detected despite programmed parameters indicating that it is programmed “ON.” Thus, an ILR implanted for a syncope indication was unable to detect pauses, leaving the patient vulnerable to delayed medical intervention or missed diagnosis of significant bradycardia or pauses. A software update was provided by Medtronic, Inc. and was made available in November 2021 to correct this issue with the LINQ I. Although Medtronic assumed this software defect was limited to the LINQ I, our device clinic was one of the first in the United States to identify and report partial electrical resets in patients with the LINQ II. With partial electrical resets the LINQ II is unable to detect or report pause, bradycardia, or premature ventricular contraction events, although patient-triggered events will still record an electrocardiogram. No software update for LINQ II was made available by Medtronic. Therefore, LINQ IIs had to be taken out of circulation. This left patients who received the device for a syncope indication to consider replacing the ILR if continued monitoring was desired. LINQ IIs became available again in June 2021 after updated manufacturing, cleared by the U.S. Food and Drug Administration, to correct the issue was implemented by the company. Our remote monitoring team received a series of alerts via CareLinkTM (Figure 1A ), in patients who recently underwent a cardioversion for AF in late 2022. All patients needed to be brought back to the device clinic for reprogramming to clear the electrical reset error (code 4522) with a Medtronic programmer (Figure 1B). It became apparent that we needed to implement a strategy to prevent further electrical resets in our patients with LINQ ILRs who undergo cardioversion, especially since they may not be performed by our EP staff. Educating clinical staff to identify patients with an ILR prior to cardioversion and appropriately placing external defibrillator pads for cardioversion away from the ILR are essential. Recent data by Eid and colleagues3Eid M. Jazar D.A. Ankit Medhekar et al.Anterior-Posterior versus anterior-lateral electrodes position for electrical cardioversion of atrial fibrillation: A meta-analysis of randomized controlled trials.Int J Cardiol Heart Vasc. 2022; 43: 101129Google Scholar showed pad placement, anterior-posterior or anterior-lateral, had no difference in the success rates of AF conversion to sinus rhythm in patients undergoing direct current cardioversions. Key takeaway messages from our device clinic staff discussion included the following: (1) communication from physicians to schedulers when booking cardioversions for patients with an ILR; (2) communicating to the hospital nursing team and advanced practice providers; (3) educating patients to disclose ILR presence to hospital staff prior to cardioversion; and (4) interprofessional communication using a simple checklist-style tool4Lingard L.A. Evaluation of a preoperative checklist and team briefing among surgeons, nurses, and anesthesiologists to reduce failures in communication.Arch Surg. 2008; 143: 1Crossref Scopus (456) Google Scholar used across different clinical units, including the EP lab, can reduce failures in communication and avoid preventable ILR electrical reset events.