Syncope is a frequent and sometimes challenging clinical symptom, for the management of which would be ideal to ascertain what was occurring during the spontaneous event.1 Unfortunately, in reality, it is a rare opportunity. Given the short duration of syncope episodes, patients are usually symptom-free during the subsequent medical observation, so that the diagnosis may not be obvious. Furthermore, the provocation tests available for patients' assessment are hampered by lack of sensitivity2 and predictive value.3,4 Because cardiac arrhythmias are among the most significant causes of syncope,5 electrocardiographic (ECG) documentation of the spontaneous episode is recognized as a diagnostic gold standard,1,6 allowing a mechanism-based treatment (arrhythmia detected) or patient's reassurance (arrhythmia excluded). On the other hand, the majority of patients with syncope present with rare (over months or even years) spontaneous recurrences leading compliance issues with any external device in the setting of a long-term ECG monitoring strategy. The above considerations were the background for the insertable loop recorder (ILR) development. The ILR is a programmable device which is placed under the skin in the upper chest with a short, outpatient procedure. It has two electrodes on its body and it is equipped of a retrospective (loop) memory that continuously records and deletes the patient's subcutaneous ECG. Such features are particularly important for the evaluation of syncope, encompassing any issue related to patients' compliance and allowing long-term ECG monitoring even when the device is activated after the patient has gained consciousness. The first ILR device (Medtronic Reveal® model 9525, Minneapolis, MN, USA), which was only able to capture retrospective ECG recordings after ‘activation’ by means of an external, hand-held device (Patient Activator), was released in 1998. Two ECG signal storage modes were allowed: (i) a 21 min mode capturing a single event … *Corresponding author. Tel: +39 0 55 7192364, Fax: +39 55 7192399, Email: angelobartoletti{at}alice.it