Implantable loop recorders in the real world: a study of two Canadian centers
- 453 Downloads
Implantable loop recorders (ILRs) are increasingly being used for ambulatory electrocardiography. We sought to evaluate ILR indications, diagnostic yield, ILR-guided interventions, and complications in two Canadian centers.
This was a retrospective study using electronic medical records to identify ILR implants at Queen’s University and the University of Manitoba. Information was collected on patient characteristics, medications, indication for implant, results of prior investigations, diagnostic outcome, and subsequent management.
A total of 540 patients were identified; 386 had completed monitoring at time of analysis. Forty patients were lost to follow-up. Indications were unexplained syncope 84.8%, palpitations 12.8%, and suspected atrial fibrillation 11.7%. For syncope, ILRs documented arrhythmia or conduction disorder in 46%. Most common conditions were asystole/sinus pause (22%), complete heart block (10.4%), and atrial fibrillation (AF) (6.9%). After ILR diagnosis, 39.9% of implanted patients received pacemaker/ICD and 2.7% underwent catheter ablation. For palpitations, ILRs documented arrhythmia or conduction disorder in 60.4%. Most common conditions were AVNRT, AF, complete heart block, and ventricular tachycardia. After diagnosis, 25% underwent catheter ablation and 22.9% received pacemaker/ICD. For suspected AF, AF was diagnosed in 40%. Complications were observed in 3.3% of implanted patients: implant site infection 1.5%, non-infectious implant site pain requiring device removal or pocket revision 1.5%, 0.2% hypertrophic scar, and 0.2% device malfunction.
An ILR has excellent diagnostic yield for syncope, palpitations, and suspected AF, and a considerable proportion of patients undergo ILR-directed interventions following monitoring. ILR implantation is a low-risk procedure.
KeywordsImplantable loop recorder Syncope Palpitations Atrial fibrillation
This research did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors.
Compliance with ethical standards
Conflict of Interest
The authors declare that they have no conflict of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. For this type of study formal consent is not required.
- 6.Edvardsson N, Frykman V, van Mechelen R, Mitro P, Mohii-Oskarsson A, Pasquié J-L, et al. Use of an implantable loop recorder to increase the diagnostic yield in unexplained syncope: results from the PICTURE registry. Europace. 2011;13:262–9. https://doi.org/10.1093/europace/euq418.CrossRefPubMedGoogle Scholar
- 9.Giada F, Gulizia M, Francese M, Croci F, Santangelo L, Santomauro M, et al. Recurrent unexplained palpitations (RUP) study comparison of implantable loop recorder versus conventional diagnostic strategy. J Am Coll Cardiol. 2007;49:1951–6. https://doi.org/10.1016/j.jacc.2007.02.036.CrossRefPubMedGoogle Scholar
- 12.Glotzer TV, Daoud EG, Wyse DG, Singer DE, Ezekowitz MD, Hilker C, et al. The relationship between daily atrial tachyarrhythmia burden from implantable device diagnostics and stroke risk: the TRENDS study. Circ Arrhythm Electrophysiol. 2009;2:474–80. https://doi.org/10.1161/CIRCEP.109.849638.CrossRefPubMedGoogle Scholar
- 13.Boriani G, Glotzer TV, Santini M, West TM, De Melis M, Sepsi M, et al. Device-detected atrial fibrillation and risk for stroke: an analysis of 10,000 patients from the SOS AF project (Stroke preventiOn Strategies based on Atrial Fibrillation information from implanted devices). Eur Heart J. 2014;35:508–16. https://doi.org/10.1093/eurheartj/eht491.CrossRefPubMedGoogle Scholar
- 15.Shen W-K, Sheldon RS, Benditt DG, Cohen MI, Forman DE, Goldberger ZD, et al. 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on clinical practice guidelines, and the Heart Rhythm Society 2017. https://doi.org/10.1016/j.hrthm.2017.03.005.
- 17.Camm AJ, Kirchhof P, Lip GYH, Schotten U, Savelieva I, Ernst S, et al. Guidelines for the management of atrial fibrillation: the task force for the management of atrial fibrillation of the European Society of Cardiology (ESC). Europace. 2010;12:1360–420. https://doi.org/10.1093/europace/euq350.CrossRefPubMedGoogle Scholar
- 24.Podoleanu C, DaCosta A, Defaye P, Taieb J, Galley D, Bru P, et al. Early use of an implantable loop recorder in syncope evaluation: a randomized study in the context of the French healthcare system (FRESH study). Arch Cardiovasc Dis. 2014;107:546–52. https://doi.org/10.1016/j.acvd.2014.05.009.CrossRefPubMedGoogle Scholar
- 27.Maggi R, Rafanelli M, Ceccofiglio A, Solari D, Brignole M, Ungar A, et al. Additional diagnostic value of implantable loop recorder in patients with initial diagnosis of real or apparent transient loss of consciousness of uncertain origin. Europace. 2014;16:1226–30. https://doi.org/10.1093/europace/euu051.CrossRefPubMedGoogle Scholar
- 31.Attanasio P, Huemer M, Loehr L, Parwani AS, Boldt L-H, Haverkamp W, et al. Use of a patient-activated event recording system in patients with tachycardic palpitations: how long to follow up? Ann Noninvasive Electrocardiol. 2015;20:566–9. https://doi.org/10.1111/anec.12301.CrossRefPubMedGoogle Scholar
- 33.Baranchuk A. Sleep apnea, cardiac arrhythmias, and conduction disorders. J Electrocardiol. 2012;45:508–12. https://doi.org/10.1016/j.jelectrocard.2012.03.003.CrossRefPubMedGoogle Scholar
- 37.Pokushalov E, Romanov A, Corbucci G, Artyomenko S, Turov A, Shirokova N, et al. Ablation of paroxysmal and persistent atrial fibrillation: 1-year follow-up through continuous subcutaneous monitoring. J Cardiovasc Electrophysiol. 2011;22:369–75. https://doi.org/10.1111/j.1540-8167.2010.01923.x.CrossRefPubMedGoogle Scholar
- 38.Hanke T, Charitos EI, Stierle U, Karluss A, Kraatz E, Graf B, et al. Twenty-four-hour Holter monitor follow-up does not provide accurate heart rhythm status after surgical atrial fibrillation ablation therapy: up to 12 months experience with a novel permanently implantable heart rhythm monitor device. Circulation. 2009;120:S177–84. https://doi.org/10.1161/CIRCULATIONAHA.108.838474.CrossRefPubMedGoogle Scholar
- 39.Pokushalov E, Romanov A, Corbucci G, Artyomenko S, Turov A, Shirokova N, et al. Use of an implantable monitor to detect arrhythmia recurrences and select patients for early repeat catheter ablation for atrial fibrillation: a pilot study. Circ Arrhythm Electrophysiol. 2011;4:823–31. https://doi.org/10.1161/CIRCEP.111.964809.CrossRefPubMedGoogle Scholar
- 41.Drew D, Borici-Mazi R, Baranchuk A. Implantable loop recorder hypersensitivity. J Innov Card Rhythm Manag. 2015;6:2109–11.Google Scholar