Int J Arrhythm.  2022 Sep;23(3):17. 10.1186/s42444-022-00068-w.

Diagnostic usefulness of implantable loop recorder in patients with unexplained syncope or palpitation

• Choi Y
• Choi J
• Kim Y
• Min K
• Roh S
• Shim J
• Choi J
• Kim Y

• KMID: 2534091
• DOI: http://doi.org/10.1186/s42444-022-00068-w

Abstract

Background
In a substantial proportion of patients with syncope, the exact cause is not identified because of the difficulty to document electrocardiograms correlated with the events during a syncope episode. Thus, an implant‑ able loop recorder (ILR) was introduced for diagnosing hidden arrhythmia; however, its clinical use remains limited. Therefore, we conducted a retrospective analysis to assess the diagnostic value of the ILR in patients with unexplained syncope or palpitations.
Methods
All patients who had undergone ILR implantation from May 2016 to January 2020, were studied retrospec‑ tively. We analyzed their electrocardiogram stored in the device.
Results
Among the 70 patients (mean age ± SD; 50.2 ± 20.3 years, 27 men) with unknown causes of syncope or pal‑ pitation, during two years follow-up, arrhythmia was detected in 26 patients (37.1%). Nineteen (73.1%) patients under‑ went permanent pacemaker implantation due to symptomatic bradycardia or atrioventricular block. All arrhythmias were detected within 6 days to 39 months after loop recorder implantation. Thirteen patients (50%) showed sick sinus syndrome (eight long pauses and five tachycardia-bradycardia syndromes). Eleven patients (42.3%) had paroxysmal atrioventricular block. Two patients who underwent permanent pacemaker implantation showed a positive tilt-table test. Three patients underwent radiofrequency catheter ablation for paroxysmal supraventricular tachycardia and atrial fibrillation. The mean duration for the detection of first sign (arrhythmia or palpitations) was 7.5 months, and the time from the detection of arrhythmia to ablation or device implantation was 3.4 months.
Conclusion
ILR monitoring detected a substantial number of significant bradycardias in patients with unexplained syncope and palpitations, suggesting that it is an effective diagnostic method that can shorten the time required to identify the cause of arrhythmias.

Keyword

Implantable loop recorder; Syncope; Pacemaker implantation