Cardiac Syncope: An Underestimated Cause of Unexplained Syncope in the Elderly-Data from a Single High-Volume Syncope Unit

<b>Background/Objectives</b>: Syncope remains a common problem in the elderly, adversely affecting quality of life, morbidity and mortality. Diagnosis is challenging due to the atypical presentation, multifactorial aetiology, overlap with non-syncoptic falls and increased prevalence of cardiac disease. This study aims to investigate the impact of cardiac syncope in this high-risk population. <b>Methods</b>: A retrospective single-centre observational cohort study, including 171 patients ≥65 years old with syncope of unknown origin or other falls, was conducted. Different diagnostic tests and strategies were utilised during the investigational process, based on clinical judgement and the latest guidelines. Patients were classified either in the 'high risk' ('cardiac') or 'low-risk' ('autonomic') pathway. <b>Results</b>: Mean age was 76.4 ± 6.6 years (range: 65-92 years old) and the mean follow-up period was 40.5 months. Our study population was characterised by a high incidence of comorbidities and underlying heart disease, and polypharmacy. One third of the patients did not report prodromals, 81.9% had no recognisable trigger and 43.3% had various 12-lead ECG abnormalities. Overall, 67.8% of the patients were stratified in the 'cardiac pathway'. Eventually, a final diagnosis was established in 126 patients (73.7%). The cause was cardiac syncope in 56.4%, reflex syncope in 26.2%, orthostatic hypotension in 7.9% and non-syncopal falls in 9.5%. An ILR was implanted in 90.1% with a diagnostic yield of 43%. ECG-based diagnosis occurred in 53.2% whereas time to diagnosis was 4.8 ± 3.3 months. <b>Conclusions</b>: Cardiac disease, mostly arrythmias, represent a common and possibly underestimated cause of unexplained syncope in the elderly. A structured approach including a targeted use of ILRs improves investigational process.