Selective use of implatable loop recorders improves diagnostic potential for unexplained syncope

Abstract Background Syncope remains a common medical problem with significant socio-economic consequences. Recently, the role of dedicated Syncope Units (SU) and implantable loop recorders (ILR) has emerged, in the investigation of unexplained syncope. Purpose To investigate the possibilities for a more rational and targeted use of various diagnostic tools. Methods In this retrospective study, 196 patients with Unexplained Syncope admitted in a single SU, between March 2019 and February 2023 were included. Various diagnostic tools were utilised during the investigational process, according to clinical judgement. Patients were retrospectively allocated into Group A including those who, among other tests, underwent ILR insertion and Group B including patients investigated without ILR implantation. Data were also compared with Group C, including patients assessed prior to SU establishment. Results There was no difference between Group A (n=133) and Group B (n=63) in the diagnostic yield (74% vs. 76%, p=0.22). There was significant difference between Group A and B regarding age (67.3 ± 16.9 years vs. 48.3 ± 19.1 years, p<0.001) and regarding cause of syncope (cardiogenic in 69% of group A and reflex syncope in 77% of group B, p<0.001). The diagnosis was based on electrocardiography (ECG) in 55% of group A and in 19% of group B (p<0.001). Time to diagnosis was 4.2 ± 2.7 months in patients with ILR implantation and 7.5 ± 5.6 months in Group B, p<0.001. In Group C, the diagnostic yield was 57.9% and the ECG-based diagnostic yield was 18.3%. Conclusions A selective use of ILR according to the clinical and electrocardiographic characteristics represents an acceptable diagnostic pathway that increases the effectiveness of the structured SU-approach by further preserving financial resources