What is the treatment for supraventricular tachycardia (SVT)?

Treatment of Supraventricular Tachycardia (SVT)

The treatment of supraventricular tachycardia should follow a stepwise approach, beginning with vagal maneuvers as first-line therapy, followed by adenosine for acute termination, and progressing to cardioversion for refractory cases, with catheter ablation being the most effective long-term solution for recurrent episodes. 1

Acute Management Algorithm

Hemodynamically Stable Patients

1. First-line: Vagal Maneuvers (Class I, Level B-R) 1

   • Valsalva maneuver: Patient bears down against closed glottis for 10-30 seconds (equivalent to 30-40 mmHg pressure)
   • Modified Valsalva: Standard Valsalva followed by supine repositioning and passive leg raise (increases success rate from 17% to 43%) 2
   • Carotid sinus massage: Apply steady pressure over carotid sinus for 5-10 seconds after confirming absence of bruits
   • Ice-cold wet towel to the face (based on diving reflex)
   • Overall success rate of vagal maneuvers: approximately 28% 1

2. Second-line: Adenosine IV (Class I, Level B-R) 1

   • Highly effective (approximately 95% success rate)
   • Also serves diagnostic purpose by unmasking atrial activity in other arrhythmias
   • Caution: Very short half-life with transient side effects (chest discomfort, flushing)

3. Third-line: IV Calcium Channel Blockers or Beta Blockers (Class IIa, Level B-R) 1, 3

   • Verapamil or diltiazem: Particularly effective for AVNRT
   • Beta blockers (metoprolol, propranolol): Good safety profile
   • Caution: Ensure absence of VT or pre-excited AF before administration to avoid hemodynamic compromise

4. Fourth-line: Synchronized Cardioversion (Class I, Level B-NR) 1

   • Indicated when pharmacological therapy fails or is contraindicated
   • Highly effective for terminating SVT

Hemodynamically Unstable Patients

• Immediate synchronized cardioversion (Class I, Level B-NR) 1
• Do not delay with vagal maneuvers or medications

Long-Term Management Options

Catheter Ablation

• First-line therapy for recurrent, symptomatic SVT (Class I, Level B-R) 3, 4
• Success rates: 94-98.5% with a single procedure 4
• Lower success and higher recurrence rates in patients with structural heart disease 3

Pharmacological Options

1. Beta blockers (metoprolol, propranolol)

   • First-line pharmacological option for ongoing management 3
   • Well-tolerated with excellent safety profile

2. Calcium channel blockers (verapamil, diltiazem)

   • Alternative for patients who cannot tolerate beta blockers

3. Class IC antiarrhythmics

   • Flecainide: Indicated for prevention of PSVT in patients without structural heart disease 5
   • Contraindicated in patients with recent myocardial infarction or structural heart disease 5

4. Class III antiarrhythmics

   • Amiodarone: Consider for refractory cases 3

Special Considerations

Common Pitfalls to Avoid

• Administering verapamil or diltiazem for VT or pre-excited AF (can lead to hemodynamic compromise or accelerated ventricular rate) 1
• Applying pressure to eyeballs (dangerous and abandoned practice) 1
• Underestimating the potential for proarrhythmic effects with antiarrhythmic medications, especially flecainide 5

Patient Education

• Teach patients how to perform vagal maneuvers safely at home for recurrent episodes
• The modified Valsalva maneuver (with leg elevation and supine positioning) has superior efficacy and can be taught to patients 2
• Patients should be referred to a heart rhythm specialist after initial treatment 6

By following this evidence-based approach to SVT management, clinicians can effectively terminate acute episodes and provide appropriate long-term solutions to reduce recurrence and improve quality of life.