Clinical Images: Diagnosis of Syncope

A 54-year-old woman presents with history of multiple sclerosis and syncope of unknown etiology. An implantable loop recorder (Reveal^® XT, Medtronic, Inc.) was inserted and demonstrated profound bradycardia with heart rate in the 10- to 20-beat range correlating with the syncope. Figure 1 shows marked sinus bradycardia and evidence muscle artifact suggestive of seizure-like activity, possibly as a result of a cerebral hypoperfusion. This demonstrates how an implantable loop recorder provides high-quality electrograms helpful in diagnosis of syncope of unknown etiology.

Disclosures: The authors have no conflicts of interest to report regarding the content herein.