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

Abstract Background and objective Syncope is a common condition and complex to diagnose. The yield of the 24 h-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 6006 consecutive patients sent to our unit for 24 h-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 24 h-Holter ECG monitoring presents a limited diagnostic and prognostic yield in unselected patients with syncope.