Other diagnostic studies-syncope

(consider based on results of H&P and ECG)

• Ambulatory ECG monitoring: if suspect arrhythmogenic syncope Holter monitoring (continuous ECG 24–72 h): useful if frequent events Event recorder (activated by Pt to record rhythm): limited role if LOC w/o prodrome External loop recorder (continuously saves rhythm, ∴ can be activated after an event): useful for episodes (including w/o prodrome) likely to occur w/in 2–6 wks; can be coupled w/ mobile cardiac telemetry than can be auto-triggered for specific rhythms External patch recorder (1-lead recording; saves for 1–4 wks): Pt-activated or auto-triggered; more comfortable for Pts Implantable loop recorders (SC; can record 2–3 y; can be triggered): useful if episodes <1/mo; dx in 55% of cases; recommended for recurrent syncope w/o prodrome
• Echo: consider to r/o structural heart disease (eg, CMP [incl HCMP & ARVC], valvular disease [incl AS, MS, MVP], myxoma, amyloid, PHT, ± anomalous coronaries)
• ETT/CCTA/Cath: esp. w/ exertional syncope; r/o ischemia or catechol-induced arrhythmia
• Electrophysiologic studies (EPS): consider in high-risk Pts in whom tachy or brady etiology is strongly suspected (eg, prior MI), but cannot be confirmed; avoid if ECG/Echo normal. 50% abnl (inducible VT, conduction abnormalities) if heart disease, but ? significance 3–20% abnl if abnl ECG; <1% abnl if normal heart and normal ECG
• Tilt table: debated utility due to poor Se/Sp/reproducibility; consider if suspected neuro- cardiogenic, orthostatic HoTN, POTS, or psychogenic, and initial eval unrevealing
• Cardiac MRI: helpful to dx sarcoid or ARVC if suggestive ECG, echo (RV dysfxn) or ⊕ FHx
• Neurologic studies (cerebrovascular studies, CT, MRI, EEG): if H&P suggestive; low yield