Evidence-based On-call

Syncope

Investigations

There is no clear benefit from electrophysiologic studies ^b

Why?

Electrophysiologic studies detect abnormal rhythms in many patients with unexplained syncope ^c , but few are true arrhythmias (24%: 95% CI: 4% to 43%) and EPS induces many unrelated ones (14%: 95% CI: 0% to 30%) ^b
Abnormal studies do not clearly predict further syncopal episodes or mortality. ^c
20% of patients require DC cardioversion out of induced arrhythmias ^b