Wolff-Parkinson-White Syndrome

 

 

Anesthetic Considerations

 

  • Potential for perioperative SVT or atrial fibrillation:

    • Consider crash cart, defbrillator pads, invasive arterial access, emergency drugs (procainamide, amiodarone)

    • Avoid AV nodal blockers if atrial fibrillation

  • Avoid sympathetic stimulation: pain, anxiety, hypovolemia, ketamine 

 

 

Goals

 

  • Identify patients with WPW 

  • Minimize sympathetic stimulation & drugs (adenosine, beta blockers, calcium channel blockers, digoxin) that could enhance anterograde conduction of cardiac impulses through the accessory pathways 

  • Reduce anxiety which may precipitate tachycardia 

 

 

Arrhythmia Treatments

 

  • Acute termination of orthodromic AVRT (approach is same as the usual patient with SVT):

    • ​1st line: vagal maneouvers, verapamil (5mg IV q3min up to 15mg), adenosine (6-12mg IV bolus with flush) 

    • 2nd line: procainamide, beta blockers, digoxin, amiodarone (prolongs the refractoriness of all cardiac tissues)

  • Acute termination of antidromic AVRT

    • ​If unstable, must cardiovert 

    • Avoid AV nodal blocking agents

    • If stable: IV drug of choice for acute treatment to terminate known antidromic AVRT is procainamide.

      • Procainamide is typically infused intravenously at 20 to 50 mg/minute given while monitoring the blood pressure closely every 5 to 10 minutes until the arrhythmia terminates, hypotension ensues, the QRS is prolonged by more than 50 percent, or a total of 17 mg/kg (1.2 g for a 70 kg patient) has been given

  • Acute termination of atrial fibrillation with pre-excitation:

    • ​AV nodal blocking drugs (adenosine, verapamil, beta blockers, & digoxin) should be avoided in patients with preexcited atrial fibrillation since blocking the AV node will promote conduction down the accessory pathway & may sometimes directly enhance the rate of conduction over the accessory pathway

    • The goals of acute drug therapy for preexcited AF are prompt control of the ventricular response & ideally, termination of atrial fibrillation

    • If unstable, must cardiovert 

    • If stable, careful trial of IV drugs (no clear 1st line drug):

      • Procainamide (Class IA): 20-50mg/min until arrhythmia suppressed, hypotension ensues, QRS prolonged by 50% of original duration or total fo 17mg/kg has been given

      • Amiodarone (Class III): first dose 150mg over 10min, then 1mg/min for 6hrs, then 0.5mg/min for 18hrs

      • Ibutilide (Class III): if patient <60kg, 0.01mg/kg over 10min; if >60kg, 1mg over 10min

 

 

ECG Features 

 

  • Short PR, wide QRS, delta wave