A 45-year-old man with WPW syndrome on ECG (delta waves, short PR) is found to have pre-excited AF during Holter monitoring with the shortest pre-excited RR interval of 200 ms. He has no symptoms of syncope or palpitations. What does this finding imply and what management is recommended?

• A Asymptomatic WPW requires no intervention regardless of pre-excited RR interval
• B Flecainide can be used to slow conduction and prevent AF in WPW
• C IV adenosine is the drug of choice to terminate pre-excited AF
• D Shortest pre-excited RR < 250 ms indicates high-risk accessory pathway; catheter ablation is recommended ✓

Explanation

A shortest pre-excited RR interval < 250 ms during AF identifies a high-risk accessory pathway capable of very rapid ventricular conduction, with risk of ventricular fibrillation. Current ACC/AHA/HRS guidelines (Class IIa) recommend catheter ablation in asymptomatic WPW with this electrophysiological high-risk marker. Adenosine and AV-nodal blockers (beta-blockers, verapamil, digoxin) are contraindicated in pre-excited AF as they increase accessory pathway conduction velocity.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.