How is ventricular tachycardia (VT) managed in pregnancy?

Management of Ventricular Tachycardia in Pregnancy

For ventricular tachycardia (VT) during pregnancy, immediate electrical cardioversion is recommended for hemodynamically unstable VT, while cardioselective beta-blockers are the first-line pharmacological treatment for stable VT without structural heart disease. 1

Diagnosis and Initial Assessment

• Always consider underlying causes:

  • Idiopathic VT (most commonly right ventricular outflow tract)
  • Structural heart disease
  • Peripartum cardiomyopathy (PPCM) - especially in last 6 weeks of pregnancy or early postpartum
  • Inherited arrhythmogenic disorders (evaluate family history)

• Diagnostic workup:

  • 12-lead ECG to characterize the arrhythmia
  • Echocardiography to assess cardiac structure and function
  • Consider cardiac MRI if structural heart disease suspected (without gadolinium)

Management Algorithm

1. Acute Management of VT

For Hemodynamically Unstable VT:

• Immediate electrical cardioversion (safe in all phases of pregnancy) 1
• Transfer to higher level of care with capabilities for mechanical circulatory support if needed 2

For Hemodynamically Stable VT:

• Monomorphic VT with normal cardiac structure:

  • IV sotalol or procainamide for acute conversion 1
  • IV amiodarone should be considered for VT refractory to cardioversion or other drugs 1

• VT with structural heart disease:

  • IV amiodarone should be considered (despite being FDA category D) 1
  • Close BP monitoring recommended with LV dysfunction 1

2. Long-term Management

For Idiopathic VT:

• First-line: Cardioselective beta-blockers (metoprolol) or verapamil 1
• Second-line: Sotalol or class IC agents (flecainide) if beta-blockers ineffective and no structural heart disease 1

For VT with Structural Heart Disease:

• Beta-blockers (metoprolol preferred)
• Consider amiodarone for therapy-resistant VT despite fetal risks 1
• ICD implantation should be considered for protection of maternal life in therapy-resistant VT 1

For Long QT Syndrome:

• Beta-blockers are strongly recommended during pregnancy and post-partum 1
• Post-partum period carries higher risk of cardiac arrest than pregnancy itself 1

3. Interventional Management

• Catheter ablation may be considered for drug-refractory and poorly tolerated VT 1

  • Postpone to second trimester if possible
  • Perform at experienced center with:
    • Suitable lead shielding
    • Maximal use of echo- and electro-anatomic mapping systems
    • Zero-fluoroscopy technique when possible 3

• ICD implantation:

  • Preferably before pregnancy if indicated
  • Can be safely performed during pregnancy if necessary 1
  • Consider subcutaneous ICD to avoid fluoroscopy 1

Special Considerations

Peripartum Cardiomyopathy

• Rule out PPCM in women with new-onset VT during last 6 weeks of pregnancy or early postpartum 1, 2
• Higher risk of sudden cardiac death requires aggressive management 2
• Consider early transfer to facilities with advanced heart failure capabilities 2

Medication Safety in Pregnancy

• FDA categories for anti-arrhythmic drugs 1:
  • Category B: Sotalol, lidocaine
  • Category C: Metoprolol, propranolol, verapamil, flecainide, propafenone
  • Category D: Amiodarone (use only when benefits outweigh risks)

Delivery Planning

• Vaginal delivery is preferred if patient is hemodynamically stable 2
• Cesarean section for obstetric indications or emergency cardiac reasons 2
• Multidisciplinary approach involving cardiology, obstetrics, anesthesiology essential 2, 4

Common Pitfalls and Caveats

1. Avoid atenolol - should not be used for any arrhythmia during pregnancy 1

2. Don't delay cardioversion for unstable VT - electrical cardioversion is safe in all phases of pregnancy 1

3. Don't miss PPCM - always consider in women with new-onset VT in late pregnancy or postpartum 1, 2

4. Beware of amiodarone - use only when other options have failed due to fetal thyroid and neurodevelopmental risks 1

5. Don't forget postpartum risk - continue monitoring and treatment postpartum, especially with long QT syndrome 1