Implantable loop recorder: evaluation of unexplained syncope

Syncope is a relatively common occurrence in the general population accounting for up to 6% of hospital medical admissions and at least 3% of accident and emergency visits each year.1 ,2 In a proportion of cases, syncope continues to pose a clinical dilemma despite the development of new diagnostic techniques. Mortality and serious morbidity associated with syncope are generally low overall but one year mortality is up to 33% in high risk groups of patients with a cardiac cause of symptoms.1 ,2 Recurrent syncope has additional deleterious effects on lifestyle, sense of physical wellbeing, and employment opportunities.3 Major obstacles to diagnosis are the intermittent nature of the symptoms, which are both periodic and often unpredictable, high spontaneous remission rates, and the lack of a diagnostic gold standard. Despite the absence of a diagnostic gold standard for syncope and a paucity of data from randomised trials, several statements have emerged from a recent position paper on clinical guidelines from the American College of Physicians.4 In summary, these guidelines emphasise that: