What is the initial management for a 31-week pregnant woman with atrial flutter and stable vitals?

Management of Atrial Flutter in a 31-Week Pregnant Woman

For a 31-week pregnant woman with atrial flutter and stable vitals, immediate electrical cardioversion is the recommended first-line treatment to restore sinus rhythm and prevent maternal and fetal hemodynamic compromise. 1, 2

Initial Assessment and Management

• Identify underlying causes: Atrial flutter during pregnancy is rare and typically associated with structural heart disease or hyperthyroidism, which should be investigated as first priorities 1, 2

• Hemodynamic status evaluation: Despite currently stable vitals, atrial flutter can lead to serious hemodynamic consequences for both mother and fetus due to rapid ventricular response 1, 2

• Electrical cardioversion:

  • First-line therapy for atrial flutter in pregnancy, even with stable vitals, due to risk of deterioration 1, 2
  • Safe during all stages of pregnancy 3, 4
  • Use 50-100J synchronized cardioversion 4
  • Continuous fetal heart rate monitoring should be performed before and after cardioversion 2

Anticoagulation Considerations

• Duration <48 hours with no risk factors: Administer IV heparin or weight-adjusted therapeutic dose LMWH pericardioversion 1

• Duration ≥48 hours or unknown duration:

  • Anticoagulation with LMWH (preferred in pregnancy) for at least 3 weeks before elective cardioversion 1, 2
  • Alternatively, perform transesophageal echocardiography to exclude left atrial thrombus 1
  • Continue anticoagulation for at least 4 weeks post-cardioversion due to risk of thromboembolism from "atrial stunning" 1, 2

Rate Control (If Cardioversion Delayed)

• First-line: Selective beta-1 blockers (metoprolol preferred, avoid atenolol) 1, 2

• Second-line: Digoxin may be used for ventricular rate control if beta-blockers are ineffective or contraindicated 1, 2

• Third-line: Non-dihydropyridine calcium channel blockers (verapamil, diltiazem) may be considered with caution 1, 2

Pharmacological Cardioversion (If Electrical Cardioversion Unavailable)

• First-line: IV ibutilide or flecainide may be considered for pharmacological termination in hemodynamically stable patients 1, 2

• Alternative options: IV propafenone may be considered only if other attempts at cardioversion fail 1

• Avoid: Amiodarone should be used only when all other therapies have failed due to fetotoxic effects 1, 2

Long-term Management

• Prophylactic antiarrhythmic therapy: Consider if symptoms are intolerable or if there is risk of recurrence 1

  • First-line: Digoxin or selective beta-blockers (metoprolol) 1, 2
  • Second-line: Sotalol, flecainide, or propafenone 1, 2

• Anticoagulation: Continue based on thromboembolic risk factors using LMWH during pregnancy 1, 2

Important Pitfalls to Avoid

• Delayed intervention: Even with stable vitals, prompt intervention is crucial as atrial flutter can rapidly deteriorate and affect fetal wellbeing 1, 3

• Inappropriate medication: Avoid amiodarone unless absolutely necessary due to fetotoxic effects 1, 2

• Inadequate monitoring: Continuous fetal heart rate monitoring is essential during and after any intervention 2, 5

• Overlooking underlying causes: Always investigate for structural heart disease or hyperthyroidism as these commonly underlie atrial flutter in pregnancy 1, 2