Wolff-Parkinson-White Syndrome (WPW)

Avoid catecholamine surges - Sympathetic stimulation shortens the accessory-pathway refractory period and speeds conduction. Ensure adequate depth before laryngoscopy, blunt the intubation response, and treat light anesthesia or pain promptly. Avoid ketamine, pancuronium, and other sympathomimetics.

AV nodal blockers are dangerous in pre-excited AF - In atrial fibrillation with pre-excitation, adenosine, calcium channel blockers, beta blockers, and digoxin block the AV node and shunt conduction down the accessory pathway, accelerating the ventricular rate and risking ventricular fibrillation. If wide, irregular complexes appear, do not give AV nodal agents.

Drug of choice for pre-excited AF - Procainamide slows accessory-pathway conduction. An unstable patient gets immediate synchronized cardioversion. Have defibrillator pads on before induction in symptomatic patients.

Orthodromic AVRT (narrow-complex) - Vagal maneuvers or adenosine are acceptable for narrow-complex orthodromic re-entry, but avoid them the moment the rhythm looks pre-excited, wide, or irregular. When in doubt, treat it as pre-excited.

Anesthetic technique - No specific agent is mandated; the goal is hemodynamic stability and avoiding tachycardia. Volatile agents and propofol are fine. Neuraxial is acceptable - treat hypotension with phenylephrine rather than ephedrine to avoid the reflex tachycardia.

Preoperative - Establish whether the patient has had curative catheter ablation. An incidental asymptomatic WPW pattern is lower-risk but still warrants avoiding triggers; have a 12-lead available and, for symptomatic or AF-history patients, pads on before induction.

A congenital pre-excitation syndrome in which an accessory pathway (bundle of Kent) directly connects the atria to the ventricles, bypassing the AV node's rate-limiting brake. The resting ECG shows a short PR interval (<120 ms) and a delta wave (slurred QRS upstroke). The pathway sets up a re-entrant circuit that produces paroxysmal SVT (AV re-entrant tachycardia, AVRT). The real danger is atrial fibrillation: conduction races down the accessory pathway unchecked, giving very fast, irregular wide-complex rates that can degenerate into ventricular fibrillation. Both sympathetic stimulation and AV-nodal-blocking drugs worsen pre-excited conduction.