[Diagnostic and prognostic efficiency of 24-hour Holter monitoring in patients with syncope].

Background And Objective: Syncope is a common condition and complex to diagnose. The yield of the 24h-Holter ECG in this context has not been clearly defined. The aim of this study was to evaluate its diagnostic and prognostic capacity in these patients.

Patients And Method: Retrospective study of 6,006 consecutive patients sent to our unit for 24h-Holter ECG monitoring for syncope. We registered the diagnostic findings and abnormal findings potentially related to an arrhythmic cause of syncope. The prognostic endpoint was a combination of death or the need for device implantation (pacemaker or defibrillator) within one year.

Results: 242 patients (4%) presented diagnostic findings and 472 (7.9%) had some abnormal findings. In 328 cases device implantation was necessary within one year, but up to 66% of these patients did not have any relevant findings on the Holter monitoring. A total of 564 patients presented the combined event, including 36.8% of patients with diagnostic findings and 8.2% without them.

Conclusions: 24h-Holter ECG monitoring presents a limited diagnostic and prognostic yield in unselected patients with syncope.