What if chemical cardioversion with dofetilide (antiarrhythmic medication) fails?

Management After Failed Chemical Cardioversion with Dofetilide

If chemical cardioversion with dofetilide fails, direct-current (electrical) cardioversion is the recommended next step in the management of atrial fibrillation. 1

Direct-Current Cardioversion Approach

• Direct-current cardioversion is recommended for patients with AF when chemical cardioversion fails and restoration of sinus rhythm is desired 1
• If the first attempt at electrical cardioversion is unsuccessful, repeated attempts may be made after:
  • Adjusting the location of the electrodes 1
  • Applying pressure over the electrodes 1
  • Administering an antiarrhythmic medication as pretreatment 1

Pretreatment Options Before Repeat Cardioversion

• Pretreatment with certain antiarrhythmic medications can be useful to enhance the success of direct-current cardioversion and prevent recurrent AF 1
• Class IIa recommendation (reasonable to perform): Use amiodarone, flecainide, ibutilide, propafenone, or sotalol as pretreatment before repeat cardioversion attempts 1
• For patients who relapse to AF after successful cardioversion, repeating the procedure following prophylactic administration of antiarrhythmic medication is reasonable 1

Anticoagulation Requirements

• For patients with AF of 48 hours duration or longer (or unknown duration), anticoagulation (INR 2.0-3.0) is recommended for at least 3 weeks prior to and 4 weeks after cardioversion 1
• For patients requiring immediate cardioversion due to hemodynamic instability, heparin should be administered concurrently and followed by oral anticoagulation for at least 4 weeks 1

Important Considerations and Precautions

• Electrical cardioversion is contraindicated in patients with digitalis toxicity or hypokalemia 1
• Frequent repetition of direct-current cardioversion is not recommended for patients who have relatively short periods of sinus rhythm between relapses despite prophylactic antiarrhythmic drug therapy 1
• Torsade de pointes is the most serious side effect of dofetilide, occurring in 0.8% of patients with supraventricular arrhythmias 2
• If considering alternative antiarrhythmic medications, be aware that digoxin and sotalol may be harmful when used for pharmacological cardioversion of AF 1

Alternative Management Strategies

• If rhythm control remains challenging despite repeated cardioversion attempts:
  • Consider AV nodal ablation with permanent ventricular pacing when pharmacological therapy is inadequate and rhythm control is not achievable (Class IIa recommendation) 1
  • AF surgical ablation procedure may be reasonable for selected patients with highly symptomatic AF not well managed with other approaches 1

Special Circumstances

• For patients with AF involving preexcitation and hemodynamic instability, immediate direct-current cardioversion is recommended 1
• In patients with ongoing myocardial ischemia, symptomatic hypotension, angina, or heart failure with rapid ventricular response, immediate R-wave synchronized direct-current cardioversion is recommended 1

Monitoring After Cardioversion

• After cardioversion, patients should be monitored for complications, particularly if they received dofetilide
• Patients receiving drugs that prolong the QT interval should be monitored in the hospital for 24 to 48 hours to evaluate the effects of heart rate slowing and allow for prompt intervention if torsades de pointes develops 1

Remember that the success rate of electrical cardioversion is higher than pharmacological cardioversion, with DC cardioversion restoring sinus rhythm instantaneously in most cases when performed properly 3.