Q; 24 year old male with no past medical history presented to ER with SVT (Supraventricular Tachycardia). Heart rate is 210. Patient was given Adenosine and went into ventricular fibrillation. CPR started and converted back to NSR (normal sinus rhythm) with cardioversion. What is your first thought?


Answer: Wolff-Parkinson-White syndrome (WPW)

People with WPW have an accessory pathway that connects the atria and the ventricles, in addition to the AV node. This accessory pathway is known as the bundle of Kent. This accessory pathway may conduct electrical activity at a significantly higher rate than the AV node particularly when it is blocked and may degenerate into venticular fibrillation.

Adenosine and other AV node blockers should be avoided including calcium channel blockers and beta blockers. Patients with atrial fibrillation and rapid ventricular response are better treated with procainamide or cardioversion in hemodynamic instability.