What are the steps to perform DC (Direct Current) cardioversion for a patient with atrial flutter?

Steps for DC Cardioversion in Atrial Flutter

Direct current (DC) cardioversion is the recommended first-line treatment for restoring sinus rhythm in patients with atrial flutter, especially when a rhythm-control strategy is being pursued or when there is hemodynamic instability.

Pre-Cardioversion Assessment and Preparation

1. Determine duration of atrial flutter:

   • If ≥48 hours or unknown duration: Anticoagulate with warfarin for at least 3 weeks before cardioversion 1
   • If <48 hours with high stroke risk: Start IV heparin, LMWH, or direct oral anticoagulant before cardioversion 1
   • If <48 hours with low stroke risk: Consider IV heparin, LMWH, direct oral anticoagulant, or no anticoagulation 1

2. Alternative approach for patients with atrial flutter ≥48 hours without 3 weeks of prior anticoagulation:

   • Perform transesophageal echocardiography (TEE) to exclude left atrial thrombus 1
   • If no thrombus is identified, proceed with cardioversion while ensuring anticoagulation is started before TEE and continued for at least 4 weeks after 1
   • Note: A normal TEE does not completely eliminate thromboembolic risk 2

3. Establish IV access and attach the following:

   • Continuous cardiac monitoring
   • Blood pressure monitoring
   • Pulse oximetry

4. Prepare emergency equipment:

   • Airway management supplies
   • Resuscitation cart with emergency medications

Procedural Steps

1. Patient positioning and preparation:

   • Position patient supine
   • Administer sedation (typically midazolam or propofol) with monitoring by qualified personnel 3
   • Apply supplemental oxygen

2. Electrode placement (two options):

   • Anterolateral position: One electrode on right upper chest and one over cardiac apex
   • Anteroposterior position: One electrode on anterior chest and one on back (may be more effective for atrial flutter)

3. Energy selection:

   • Atrial flutter typically requires lower energy than atrial fibrillation 1
   • Start with 50-100 joules for biphasic defibrillators
   • If unsuccessful, increase energy in stepwise fashion

4. Synchronization:

   • Ensure the defibrillator is in synchronized mode to avoid shock delivery during vulnerable period of cardiac cycle 1
   • Verify synchronization markers appear on R waves

5. Cardioversion delivery:

   • Ensure all personnel are clear of patient and bed
   • Press and hold discharge buttons until shock is delivered
   • Immediately assess rhythm and vital signs

6. Post-shock management:

   • If first shock fails, consider:
     • Repositioning electrodes
     • Applying pressure over electrodes
     • Increasing energy level
     • Administering antiarrhythmic medication before repeat attempt 1

Post-Cardioversion Care

1. Immediate monitoring:

   • Continuous cardiac monitoring until patient fully recovered from sedation
   • Monitor vital signs every 15 minutes until stable
   • Assess for complications (bradycardia, hypotension, arrhythmias)

2. Anticoagulation:

   • Continue anticoagulation for at least 4 weeks after successful cardioversion regardless of CHA₂DS₂-VASc score 1
   • Long-term anticoagulation should be based on thromboembolic risk profile 1

3. Antiarrhythmic therapy:

   • Consider antiarrhythmic medications to maintain sinus rhythm if high risk of recurrence 1
   • Options include flecainide, propafenone, dofetilide, sotalol, or amiodaride based on patient's cardiac status 1

Special Considerations

1. Hemodynamically unstable patients:

   • Proceed immediately to synchronized cardioversion 1
   • Anticoagulate as soon as possible and continue for at least 4 weeks 1

2. Patients with pacing wires or implanted devices:

   • Consider rapid atrial pacing as an alternative to electrical cardioversion 1
   • Pace at a rate 5-10% above the atrial flutter rate for ≥15 seconds 1
   • Incrementally increase pacing rate until sinus rhythm or atrial fibrillation occurs 1

3. Pre-excitation syndromes:

   • Avoid AV nodal blocking agents (digoxin, calcium channel blockers, beta-blockers) 1, 4
   • Proceed directly to cardioversion if hemodynamically unstable 1

Potential Complications

• Thromboembolism (0.6-3% risk without adequate anticoagulation) 2, 5
• Bradyarrhythmias or tachyarrhythmias
• Skin burns at electrode sites
• Sedation-related complications (respiratory depression, hypotension)

Follow-up

• Schedule follow-up within 10 days of discharge 4
• Monitor for recurrence of atrial flutter
• Assess effectiveness of rate or rhythm control strategy
• Consider repeated cardioversion if patient maintains sinus rhythm for clinically meaningful periods between procedures 1