What is the treatment for Paroxysmal Supraventricular Tachycardia (PSVT)?

Treatment of Paroxysmal Supraventricular Tachycardia (PSVT)

For paroxysmal supraventricular tachycardia (PSVT), the first-line treatment is vagal maneuvers for hemodynamically stable patients, followed by adenosine if vagal maneuvers fail, while synchronized cardioversion is indicated for hemodynamically unstable patients. 1

Acute Management Algorithm

Step 1: Assess Hemodynamic Stability

• If hemodynamically unstable (hypotension, altered mental status, signs of shock):

  • Proceed directly to synchronized electrical cardioversion (Class I, Level B-NR) 1, 2
  • Do not delay cardioversion to administer medications 1

• If hemodynamically stable:

  • Proceed to Step 2

Step 2: Vagal Maneuvers (Class I, Level B-R)

• First-line intervention with approximately 27.7% success rate 1
• Techniques include:
  • Modified Valsalva maneuver (43% effective) 2, 3
  • Carotid sinus massage (in appropriate patients)
  • Facial application of cold towel
  • Warning: Do not attempt vagal maneuvers in hypotensive patients 1

Step 3: Pharmacological Treatment (if vagal maneuvers fail)

1. Adenosine (Class I, Level B-R)

   • First-line medication with 91% success rate 1, 2
   • Acts as both diagnostic and therapeutic agent

2. If adenosine fails, use (Class IIa, Level B-R):

   • IV calcium channel blockers (non-dihydropyridine)

     • Diltiazem or Verapamil
     • Avoid in patients with pre-excited atrial fibrillation, ventricular tachycardia, significant LV dysfunction, PR interval >0.24 seconds, or second/third-degree AV block without pacemaker 1

   • IV beta blockers

     • Metoprolol or Esmolol

3. Synchronized cardioversion if pharmacological therapy fails (Class I, Level B-NR) 1

Long-Term Management

Pharmacological Prevention

• Beta blockers or non-dihydropyridine calcium channel blockers (Class I, Level B-R) 1
• Class IC antiarrhythmics for patients without structural heart disease (Class I, Level B-R):
  • Flecainide: Indicated for PSVT prevention in patients without structural heart disease 1, 4
  • Propafenone: Effective for PSVT prevention (47-67% attack-free rate) 5
• Ivabradine (2.5-7.5 mg twice daily) is a reasonable option (Class IIa, Level B-R) 1

Definitive Treatment

• Catheter ablation (Class I, Level B-NR) 1
  • Success rates of 94-98% 1, 2
  • Provides potential cure without need for chronic medications
  • Recommended as first-line therapy to prevent recurrence 2
  • Refer to cardiology/electrophysiology within 1-2 weeks after initial presentation 1

Special Considerations

Pregnancy

• Adenosine is safe due to short half-life
• Use lowest recommended medication doses
• Avoid medications in first trimester if possible 1

End-Stage Renal Disease

• Monitor for electrolyte abnormalities
• Be aware of dialysis-related fluid shifts triggering arrhythmias 1

Important Warnings and Contraindications

• Never use dihydropyridine calcium channel blockers (e.g., nifedipine) for SVT treatment (Class III: Harm) 1
• Avoid flecainide in patients with:
  • Structural heart disease
  • Ventricular dysfunction
  • Recent myocardial infarction 1, 4
• Avoid verapamil/diltiazem in patients with pre-excited atrial fibrillation or significant LV dysfunction 1
• Monitor closely when administering amiodarone IV due to hypotension risk 1

Patient Education

• Teach proper vagal maneuver techniques for home termination of episodes
• Explain warning signs requiring medical attention 1
• Discuss benefits of catheter ablation as definitive treatment