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Patient handout

Pre-excited atrial flutter (WPW) — DCCV / procainamide; AV-nodal blockers ABSOLUTELY contraindicated

PRODUCTION

1. Your condition

This handout is for pre-excited atrial flutter (wpw) — dccv / procainamide; av-nodal blockers absolutely contraindicated. Your care team identified this based on: palpitations, presyncope or syncope in a patient with known wpw / a delta wave on prior ecg — pre-excited atrial flutter/af until proven otherwise (vf risk).

Other reasons your team may use this plan: very fast (>200-250 bpm), broad-complex, often irregular tachycardia — pre-excited atrial flutter/af; distinguish from polymorphic vt and svt with aberrancy; ecg showing flutter/fibrillatory atrial activity conducting with variable broad pre-excited qrs morphology — antegrade accessory-pathway conduction; hypotension / shock / pulmonary oedema / ischaemia with a wide irregular tachycardia — unstable pre-excited tachyarrhythmia requiring immediate synchronised dccv.

2. Your medications

Take these medications exactly as prescribed. Do not stop or change a dose without talking to your provider.

MedicationStarting doseHowWhenWhat it does
Synchronised DC cardioversion100-200 J biphasic synchronised, escalate as needed (immediate if unstable; default even in many stable patients given VF risk)N/Aas needed; immediate if haemodynamic instabilityACLS 2020 + SVT guidelines — definitive, fastest, safest termination; avoids the VF risk of AV-nodal blockade entirely
procainamide15-17 mg/kg IV at ≤20-50 mg/min until arrhythmia terminates, hypotension, QRS widens >50%, or max dose; then 1-4 mg/min infusionIVloading then infusion, monitored2015 ACC/AHA/HRS + 2019 ESC SVT — prolongs accessory-pathway refractoriness and slows pre-excited conduction; preferred stable-patient agent; stop for hypotension or >50% QRS widening
ibutilide1 mg IV over 10 min (0.01 mg/kg if <60 kg), may repeat once after 10 min; continuous ECG ≥4 hIVonce, may repeat ×12019 ESC SVT — effective for pre-excited AF/flutter; correct K/Mg first; torsades risk → monitor QT ≥4 h with defibrillator available
AVOID adenosineDO NOT GIVEN/AN/ATransient AV-nodal block can increase antegrade accessory-pathway conduction and precipitate AF→VF; contraindicated in pre-excited AF/flutter (2015 ACC/AHA/HRS)
AVOID IV diltiazem/verapamil + beta-blockersDO NOT GIVEN/AN/AAV-nodal blockade preferentially channels conduction down the accessory pathway → very rapid ventricular rates and VF; contraindicated (2019 ESC SVT; 2020 ESC AF)
AVOID digoxinDO NOT GIVEN/AN/AShortens accessory-pathway refractory period and slows the AV node → accelerated pre-excited conduction; contraindicated
AVOID intravenous amiodaroneDO NOT GIVE acutelyN/AN/AIV amiodarone can cause AV-nodal block + hypotension and has been associated with acceleration to VF in pre-excited AF — avoided acutely per 2019 ESC SVT / 2020 ESC AF (DCCV or procainamide preferred)
Accessory-pathway catheter ablation (definitive)EP study + radiofrequency/cryo ablation of the accessory pathway; confirm bidirectional blockN/Adefinitive, post-stabilisation2015 ACC/AHA/HRS + 2019 ESC SVT — Class I after a pre-excited AF/flutter event; curative and removes the VF substrate

Plan: Pre-excited atrial flutter — synchronised DCCV if unstable; IV procainamide/ibutilide if stable; AV-nodal blockers ABSOLUTELY contraindicated (2015 ACC/AHA/HRS SVT; 2019 ESC SVT; 2020 ESC AF)

3. When to call your provider

Contact your care team if any of the following happen:

  • Recurrence post-ablation → repeat EP study
  • New symptoms if deferred → re-offer ablation
  • Family member with high-risk pathway → refer

4. When to seek emergency care

Call 911 or go to the nearest emergency room right away if you have:

  • Pre-excited atrial flutter/AF with hypotension, shock, ischaemia, pulmonary oedema or depressed consciousness — immediate synchronised DC cardioversion is mandatory; no time for pharmacologic trial
  • Pre-excited AF/flutter degenerating to ventricular fibrillation or polymorphic VT — the feared mechanism of sudden death in WPW
  • Adenosine, IV diltiazem/verapamil, beta-blocker, digoxin or IV amiodarone given to a patient with pre-excited AF/flutter — high risk of acceleration to VF
  • Shortest pre-excited R-R interval in AF <250 ms, multiple accessory pathways, or syncope/arrest as the presentation — markers of a high-risk pathway with elevated SCD risk
  • Repeated pre-excited AF/flutter episodes requiring multiple cardioversions within a short period — electrical storm in the pre-excited substrate

5. Follow-up

Electrophysiology: accessory-pathway ablation (curative; Class I post pre-excited AF/flutter) — confirm bidirectional pathway block; sports/occupational clearance only after successful ablation or reassuring risk stratification; family screening if SCD history; document lifelong AV-nodal-blocker avoidance until pathway eliminated; anticoagulation per CHA2DS2-VASc if AF component persists

6. Sources

Guideline: 2015 ACC/AHA/HRS SVT Guideline + 2019 ESC SVT Guideline + 2020 ESC AF Guideline + 2017 AHA/ACC/HRS VA/SCD

  1. pubmed.ncbi.nlm.nih.gov/26399663
  2. pubmed.ncbi.nlm.nih.gov/31504425
  3. pubmed.ncbi.nlm.nih.gov/32860505