What is the best course of action for a patient with atrial flutter (Aflutter) and controlled rate, presenting with respiratory distress?

Management of Atrial Flutter with Controlled Rate and Respiratory Distress

For a patient with atrial flutter, controlled rate, and respiratory distress, immediate synchronized cardioversion is recommended as the first-line treatment to restore sinus rhythm and improve respiratory status. 1, 2

Initial Assessment and Management

• Evaluate hemodynamic stability - while the patient has a "controlled rate," the presence of respiratory distress suggests clinical instability that warrants immediate intervention 1, 3
• Check anticoagulation status - if the patient has been in atrial flutter for ≥48 hours and is not adequately anticoagulated, consider risks vs. benefits of immediate cardioversion 1
• Prepare for synchronized cardioversion - atrial flutter typically requires lower energy levels than atrial fibrillation 2
• Consider pretreatment with IV magnesium to reduce risk of post-cardioversion arrhythmias 3

Cardioversion Procedure

• Perform synchronized electrical cardioversion starting at lower energy settings (50-100J) as atrial flutter often responds to lower energy than atrial fibrillation 1, 2
• If initial cardioversion is unsuccessful, increase energy in stepwise fashion 1
• Monitor for post-cardioversion complications including bradycardia or tachycardia 3

Alternative Options if Cardioversion is Delayed or Contraindicated

Rate Control Options

• IV beta blockers (esmolol preferred due to rapid onset) or calcium channel blockers (diltiazem) for temporary rate control if cardioversion must be delayed 3, 2
• For patients with systolic heart failure where beta blockers are contraindicated or ineffective, IV amiodarone can be used for acute rate control 1, 3
• Important: Avoid diltiazem and verapamil in patients with advanced heart failure, heart block, or sinus node dysfunction without pacemaker therapy 3, 2

Pharmacological Cardioversion

• IV ibutilide is effective for pharmacological cardioversion of atrial flutter (conversion rates of 53-70%) 4
• Oral dofetilide is another option for pharmacological cardioversion 1
• If pacing wires are in place (e.g., temporary pacemaker), rapid atrial pacing can be used for conversion 1

Anticoagulation Considerations

• Antithrombotic therapy should follow the same guidelines as for atrial fibrillation 1
• Risk of stroke in atrial flutter is significant, with reported rates of 3% annually 3, 5
• If atrial flutter duration is ≥48 hours or unknown, anticoagulation should be initiated before cardioversion if possible 1, 6

Long-term Management After Acute Episode

• Catheter ablation of the cavotricuspid isthmus (CTI) is the preferred definitive treatment for recurrent symptomatic atrial flutter 1
• Beta blockers, diltiazem, or verapamil are useful for long-term rate control if rhythm control is not pursued 1, 3
• Consider long-term antiarrhythmic therapy with amiodarone, dofetilide, or sotalol if catheter ablation is not an option 1, 2

Important Clinical Considerations

• Rate control can be more difficult to achieve in atrial flutter than in atrial fibrillation due to less concealed AV nodal conduction 1, 3
• Atrial flutter and atrial fibrillation frequently coexist—22-50% of patients develop atrial fibrillation within 14-30 months after CTI ablation 3, 2
• Risk factors for developing atrial fibrillation after atrial flutter ablation include prior atrial fibrillation, depressed left ventricular function, structural heart disease, and increased left atrial size 1, 2
• The underlying cause of respiratory distress should be investigated and treated (e.g., heart failure exacerbation, pneumonia) 3