Introduction: Generally available methods for the diagnosis of syncopal conditions such as Holter monitoring , the tilt test and invasive electrophysiological examinations, lead to the assessment of the cause of sporadic syncopes only in some patients. The implantable monitoring device REVEAL protracts significantly the monitoring period. Methods, results: The authors implanted the implantable monitoring device REVEAL in the cour- se of 14 months to 19 patients with syncopes of obscure origin. During this period it was possible to prove the cause of the syncope in a total of 10 patients (53 %), in 8 patients the cause was arrhythmia, in another two an arrhythmic cause was ruled out. During monitoring the authors did not record any serious undesirable events. Conclusion: Implantable monitoring devices are an asset in the diagnosis of sporadic syncopes where currently available invasive and non-invasdive methods fail. Its use in patients without obvious structural cardiovascular disorders is safe.

        Key words: Syncope - Loop recorder.