What is the next best treatment for a 22-year-old pregnant woman at 27 weeks gestation with a history of syncopal (fainting) episodes?

Management of Syncope in a Pregnant Woman at 27 Weeks Gestation

For a 22-year-old pregnant woman at 27 weeks gestation with a history of syncopal episodes, beta-blocker therapy is the next best treatment after initial evaluation to identify the underlying cause.

Initial Evaluation

Before initiating treatment, a targeted evaluation should be performed to identify the underlying cause of syncope:

• Laboratory testing: Complete blood count, electrolytes, glucose, and thyroid function tests 1
• Cardiovascular assessment: 12-lead ECG to assess for arrhythmias 1
• Red flags requiring immediate attention:
  • Focal neurological deficits
  • New-onset severe headache
  • Atypical or persistent vertigo
  • Abnormal neurological examination
  • Signs of pre-eclampsia
  • Significant cardiac symptoms 1

Treatment Algorithm

1. First-line treatment: Beta-blockers

   • Cardioselective beta-blockers (metoprolol) or propranolol are recommended for arrhythmia-related dizziness and syncope in pregnancy 2, 1
   • These medications help control heart rate and prevent tachycardia-induced syncope
   • Beta-blockers have established safety profiles in pregnancy

2. Alternative treatments if beta-blockers are contraindicated:

   • Calcium channel antagonists (diltiazem or verapamil) 2
   • Digoxin for rate control 2

3. For specific arrhythmia-related causes:

   • If atrial tachycardia is identified: Beta-blockers and/or digitalis for rate control 2
   • If atrial fibrillation is identified: Control ventricular rate with digoxin, beta-blocker, or calcium channel antagonist 2

Special Considerations

• Avoid amiodarone due to its fetotoxic effects unless other agents fail 2
• Electrical cardioversion should be considered if the patient becomes hemodynamically unstable due to arrhythmia 2
• Anticoagulation may be necessary if arrhythmia is detected, with heparin preferred over warfarin during pregnancy 2

Patient Education and Safety

• Advise patient to:
  • Avoid activities with risk of falling
  • Avoid excessive heat exposure
  • Stop physical activity and seek medical attention if dizziness persists 1
  • Maintain adequate hydration and avoid prolonged standing

Follow-up Recommendations

• Moderate symptoms: Follow-up within 1-2 weeks
• Severe symptoms: Immediate specialist referral 1
• Monitor fetal well-being regularly as syncope can potentially impact uteroplacental perfusion 3

Potential Complications

Syncope during pregnancy carries risks for both mother and fetus, including:

• Risk of injury from falls
• Uteroplacental insufficiency
• Psychological effects
• Interruptions in prenatal care 3

Beta-blockers represent the safest and most effective first-line treatment for recurrent syncope in pregnancy, with established efficacy in preventing syncopal episodes while maintaining maternal and fetal safety.