Introduction: Non-syncopal transient loss of consciousness (T-LOC) resemble syncope and differential diagnosis may be challenging. Implantable loop recorder (ILR) is useful but it has never been systematically assessed.
Methods and Results: 57 patients received an ILR, who had had 4.6±2.3 episodes of T-LOC to distinguishing epilepsy from syncope (#28) or fall from syncope (#29). During 20±13 months of follow-up, 33 patients (57%) had an ILR-documented event. An arrhythmia was documented in 15 (26%) patients: asystole in 7 patients with suspicion of epilepsy and in 5 patients with fall; atrial tachyarrhythmia in 1 and 2 patients respectively. ILR excluded an arrhythmia in 18 patients, supporting the diagnosis of epilepsy in 6 (11%), non-accidental fall in 10 (18%) patients and hypotensive syncope in 2 (3%). A diagnosis remained unexplained in 24 (42%) patients. Therapy: antiepileptic drugs in 6 (10%), pacemaker in 11 (19%), antiarrhythmic drugs in 4 (7%), reduction of hypotensive drugs in 1 patient (2%). No specific therapy in 11 patients (18%).
Conclusions: ILR provides a diagnostic value in “difficult” patients with initial diagnosis of non syncopal T-LOC.