Loop Recorder Implantation: Keeping up with the Guidelines with a Single-Centre Experience

Abstract

Introduction: Implantable loop recorders (ILR) have a retrospective memory which continuously records the patient's ECG. Patients with infrequent short duration symptoms are unlikely to be diagnosed by conventional Holter monitoring. ILR devices have become smaller and simpler to implant, allowing for improved arrhythmia detection rates. However, the most recent guidelines for ILR devices were last updated in 2009. Methods: The aim of this audit was to review the indications and outcomes for ILR devices at the Lyell McEwin Hospital. 88 consecutive ILR devices inserted from May 2014 – July 2015 and case notes were retrospectively reviewed. Follow-up was 18 - 32 months. Results: 88 ILRs were implanted with the indications of syncope (n = 43), palpitations (n = 27), stroke (n = 7), pre-syncope (n = 2), bradycardia (n = 2), hypertrophic cardiomyopathy (n = 1) and unknown indication (n = 6). 41% (n = 36) of patients received a diagnosis as a result of the ILR. 21% (n = 19) had an indication for device therapy. 9% (n = 8) were treated with an electrophysiological ablation, and 10% (n = 9) were treated medically. 86% (n = 31) of ‘diagnostic’ ILRs were inserted for investigation of either ‘syncope’ or ‘palpitations’. 59% (n = 52) of patients did not have an arrhythmia identified. 20% (n = 11) of these had the ILR removed. 41% (n = 36) are having on-going follow-up, and 6% (n = 4) were lost to follow-up. 92% of these patients (n = 48) had no recurrent symptoms after the ILR was inserted. Discussion: With improved availability of ILR devices, the diagnostic yield still compares favourably with previous pooled data when utilising the current ILR insertion guidelines.