The objective of the study was to evaluate the diagnostic yield of a loop recorder (Reveal Plus, Medtronic) in the diagnosis of syncope conditions whose aetiology remains unclear despite the performance of a full diagnostic procedure.
Patients and method: Loop recorders were implanted in 25 patients with recurrent syncope (9 men, 16 women, average age 59 +/- 14 years), who reported 4 +/- 2.7 episodes of syncope (2-10 episodes). A complete diagnostic algorithm was performed for all patients before implantation including the head-up tilt test, an invasive electrophysiological examination and a neurological examination. The aetiology of the syncope was not established by these examinations.
Results: During an average monitoring period of 13 +/- 8 months (1-24 months) 10 patients experiences recidivating syncope, 7 patients experienced pre-syncope and 1 patient experienced palpitations. 7 were asymptomatic during monitoring. Symptomatic arrhythmia was detected in 10 patients (40%). The most frequent finding was bradyarrhythmia (6 patients--sinus arrest in 3 patients, serious bradycardia in 2 patients, AV block in 1 patient). Tachyarrhythmia was the cause of symptoms in 4 patients (supraventricular tachycardia in 3 patients, ventricular bigeminy in 1 patient). In the case of 5 patients (20%) syncope (pre-syncope) took place in the absence of a serious arrhythmia and was classified as vasovagal syncope.
Conclusion: The implantable loop recorder established a diagnosis in 15 of 25 patients (60%) with syncope that was not diagnosed by conventional tests and it is a highly beneficial method for diagnosing syncope.