Cardiology, ECG

Solve This Medical Mystery

OK, residents (and ambitious students): It’s time for a friendly competition. We’re giving away a prize package to the person who submits the most accurate, thorough interpretation of this exceedingly rare EKG.


This is a case of refractory SVT in an otherwise healthy young patient. The patient would only transiently convert with vagal maneuvers and adenosine. Treatment with antidysrhythmic medications was also unsuccessful, so the patient was taken to the electrophysiology lab for mapping and ablation. EP studies showed a “retrograde only” accessory pathway with no observed spontaneous or inducible anterograde conduction. The following EKG was obtained while the patient was on a diltiazem drip.

What is your interpretation of this EKG?


This case, originally managed by Vitaliy Belyshev, MD, and John McGhee, MD, was subsequently reviewed by EMRA EKG Guide author Jeremy Berberian, MD, and ECG Pocket Brain author Ken Grauer, MD.

Can you see what they discovered after careful study?

Send your interpretation of this EKG to by March 30. Be thorough! Medical students, residents, and fellows are welcome to participate — but attendings cannot consult on the entry.

The individual who submits the most accurate interpretation 
will win Amal Mattu’s ECGs for the 
Emergency Physician (2-book set) and ECG Pocket Brain.