What is the treatment for supraventricular tachycardia (SVT)?

Treatment of Supraventricular Tachycardia (SVT)

The first-line treatment for SVT is vagal maneuvers, followed by adenosine for acute conversion, with catheter ablation being the most effective long-term solution for recurrent SVT. 1

Acute Management Algorithm

Hemodynamically Stable Patients

1. First-line: Vagal maneuvers

   • Modified Valsalva maneuver is most effective (success rate ~43%) 2, 3
   • Technique: Patient bears down against closed glottis for 10-30 seconds (equivalent to 30-40 mmHg) in supine position 1
   • Carotid sinus massage is less effective but can be attempted if Valsalva fails 1, 2

2. Second-line: Adenosine IV

   • Highly effective (91-95% success rate) 1, 3, 4
   • Dosing: Initial 6 mg rapid IV bolus; if ineffective, follow with 12 mg after 1-2 minutes
   • Advantages: Ultra-short half-life, diagnostic value 1, 5
   • Common side effects: Chest discomfort, dyspnea, flushing (transient) 5, 4
   • Contraindications: Known hypersensitivity, bronchospastic lung disease, second/third-degree AV block 5

3. Third-line: IV calcium channel blockers or beta blockers

   • Verapamil or diltiazem IV for patients without heart failure 1
   • Beta blockers IV (alternative option) 1
   • Caution: Avoid verapamil in patients with severe left ventricular dysfunction, hypotension, or those receiving beta blockers 6

Hemodynamically Unstable Patients

• Immediate synchronized cardioversion 1
• No delay for pharmacological interventions

Long-Term Management

First-line: Catheter Ablation

• Most effective long-term solution with 94-98.5% success rate 3
• Recommended for recurrent, symptomatic SVT 1
• Consider early referral for electrophysiology study with option for ablation 1

Pharmacological Options (if ablation not preferred/feasible)

1. First-line medications:

   • Oral beta blockers (metoprolol, propranolol)
   • Calcium channel blockers (diltiazem, verapamil)
   • Both effective for ongoing management in patients without pre-excitation 1

2. Second-line medications:

   • Flecainide or propafenone (for patients without structural heart disease) 1
   • Sotalol (alternative option) 1

3. Third-line medications:

   • Dofetilide (when first/second-line drugs ineffective or contraindicated) 1
   • Amiodarone (reserved for when other options fail) 1

Patient Education

• Teach patients how to perform vagal maneuvers for self-management 1
• Consider "pill-in-pocket" approach for infrequent but prolonged episodes 7
• Combination of diltiazem and propranolol has shown 94% effectiveness for patient self-administration 7

Important Considerations

• Avoid verapamil in patients with:

  • Wolff-Parkinson-White syndrome or accessory pathways 6
  • Severe left ventricular dysfunction (EF <30%) 6
  • Concomitant beta-blocker therapy 6

• Monitor for adenosine adverse effects:

  • Transient AV block, bradycardia, hypotension 5
  • Bronchospasm in susceptible patients 5
  • Rarely: seizures, cerebrovascular events 5

By following this evidence-based approach to SVT management, clinicians can effectively treat both acute episodes and provide appropriate long-term management strategies that prioritize patient morbidity, mortality, and quality of life outcomes.