Efficacy of implantable loop recorders in establishing symptom-rhythm correlation in patients with unexplained syncope

Objective: To evaluate the efficacy of the implantable loop recorder (ILR) in establishing symptom-rhythm correlation in patients with unexplained syncope.

Methods: Implantable loop recorders (ILR, Reveal Plus(9526), Medtronic Inc.) were implanted in 10 patients [aged 14 - 78 (41 +/- 22) years, 6 female] with unexplained syncope from October 2002 to May 2005. Syncopal episodes were (4.5 +/- 1.4) patients.

Results: During the monitoring period [8 - 21 (15.3 +/- 3.6) months], there were 24 times syncopal episodes in 6 patients. A total of 211 arrhythmia events were documented by ILR in 7 patients and symptom-rhythm correlation could be established in these 7 patients. In 2 patients, there were no recurrent syncopes and no arrhythmia events could be recorded. In 1 patient, syncope was caused by reasons other than arrhythmia.

Conclusions: ILR is useful in determining the presence or absence of an arrhythmia during symptoms of syncope when conventional diagnostic testing, such as electrocardiogram, Holter monitoring, and/or external loop recording, is inconclusive.