Key result
ILR monitoring documents spontaneous events in ~57% of patients with uncertain T-LOC.
Why the study?
The differential diagnosis between syncope and non-syncopal transient loss of consciousness (T-LOC) is challenging, and the diagnostic value of implantable loop recorders (ILR) in this context has not been systematically assessed.
Does an implantable loop recorder improve diagnostic yield in patients with real or apparent transient loss of consciousness of uncertain origin?
Observational (n=58)
Does an implantable loop recorder improve diagnostic yield in patients with real or apparent transient loss of consciousness of uncertain origin?
Implantable loop recorders provide significant diagnostic value in patients with transient loss of consciousness of uncertain origin, documenting events in 57% of patients and diagnosing arrhythmic syncope in 26%.
May support ILR use in uncertain syncope; leaves open need for RCTs on outcomes.
AIMS: Non-syncopal transient loss of consciousness (T-LOC) encompasses disorders that sometimes resemble syncope, and the differential diagnosis with true syncope may be challenging. The implantable loop recorder (ILR) is potentially useful, but has never been systematically assessed. The aim of the study is to evaluate the diagnostic value of ILR in distinguishing syncope from non-syncopal forms of T-LOC. METHODS AND RESULTS: We implanted an ILR in 58 patients (mean age 71 ± 17 years, 25 males) who had had 4.6 ± 2.3 episodes of real or apparent T-LOC, in order to distinguishing epilepsy from syncope (#28), unexplained fall from syncope (#29), or functional pseudo-syncope from syncope (#1). During 20 ± 13 months of follow-up, 33 patients (57%) had a spontaneous event documented by ILR. A diagnosis of syncope was established by ILR documentation of an arrhythmia in 15 (26%) patients: an asystole of 6 s (IQR 4-10 s) duration was documented at the time of the spontaneous event in seven patients with initial suspicion of epilepsy and in five patients with unexplained fall; atrial tachyarrhythmia was documented at the time of the spontaneous event in 1 and 1 patient, respectively, and ventricular tachycardia in 1 patient with unexplained fall. Conversely, in another 18 patients, ILR monitoring documented no significant rhythm abnormalities at the time of T-LOC recurrence, thus excluding an arrhythmic syncope. Finally, ILR was unable to document any syncopal episode in 25 (43%) patients. Among the 15 patients with an established diagnosis of arrhythmic syncope, syncope recurred during follow-up in 2 of 11 patients who were on pacemaker therapy and in 3 of 4 patients who were on other therapies. CONCLUSION: Implantable loop recorder monitoring provides additional diagnostic value in 'difficult' patients with an initial diagnosis of non-syncopal real or apparent T-LOC.
No takes yet. Share an insight, caveat, or question.
Maggi et al. (2014) conducted an observational in Transient loss of consciousness of uncertain origin (n=58). Implantable loop recorder was evaluated on Spontaneous event documented by ILR. Implantable loop recorder monitoring documented a spontaneous event in 57% of patients and diagnosed arrhythmic syncope in 26% of patients with uncertain transient loss of consciousness.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: