What is the treatment for Supraventricular Tachycardia (SVT)?

Treatment of Supraventricular Tachycardia (SVT)

The treatment of SVT follows a stepwise approach, starting with vagal maneuvers, followed by adenosine for acute conversion, and progressing to other pharmacological agents or synchronized cardioversion based on hemodynamic stability. 1, 2

Acute Management

First-Line Interventions

• Vagal maneuvers should be performed as the initial treatment for patients with SVT 1, 2
  • Perform in supine position using proper technique:
    • Valsalva maneuver: patient bears down against closed glottis for 10-30 seconds (equivalent to 30-40 mmHg) 1
    • Carotid sinus massage: apply steady pressure over carotid sinus for 5-10 seconds (after confirming absence of carotid bruit) 1, 2
    • Modified Valsalva maneuver has higher success rate (43.7%) compared to standard Valsalva (24.2%) 3
  • Switching between techniques can increase overall success rate to 27.7% 1, 2
  • AVOID applying pressure to eyeball as this practice is dangerous 1, 2

Second-Line Interventions

• Adenosine is recommended if vagal maneuvers fail 1, 2
  • Highly effective (91-95% success rate) for acute termination of SVT 2, 4
  • Brief side effects (chest discomfort, dyspnea, flushing) lasting <1 minute 5
  • Serves both diagnostic and therapeutic purposes 1

For Hemodynamically Stable Patients

• Intravenous calcium channel blockers (diltiazem or verapamil) are effective for acute treatment 1, 2
• Intravenous beta-blockers are reasonable alternatives 1, 2
• Synchronized cardioversion is recommended when pharmacological therapy is ineffective or contraindicated 1

For Hemodynamically Unstable Patients

• Immediate synchronized cardioversion should be performed when adenosine and vagal maneuvers don't terminate the tachycardia or aren't feasible 1, 2

Special Considerations

Pre-excited AF

• Synchronized cardioversion is first-line for hemodynamically unstable patients with pre-excited AF 1
• Ibutilide or intravenous procainamide are recommended for hemodynamically stable patients with pre-excited AF 1, 2
• AVOID AV nodal blocking agents (verapamil, diltiazem, beta-blockers) in patients with suspected pre-excitation as they may accelerate ventricular rate 2

Long-term Management

Pharmacological Options

• Oral beta-blockers, diltiazem, or verapamil are useful for ongoing management in patients without ventricular pre-excitation 1
• Flecainide or propafenone are reasonable options for patients without structural heart disease who have symptomatic SVT 1, 6
  • CAUTION: Flecainide can cause proarrhythmic effects, especially in patients with structural heart disease or recent myocardial infarction 6
• Sotalol, dofetilide, amiodarone, or digoxin may be considered in specific cases when other options are ineffective or contraindicated 1

Definitive Treatment

• Catheter ablation is highly effective (94-98% success rate) and recommended as first-line therapy to prevent recurrence of SVT 4, 7, 8
• Electrophysiological study with ablation option is useful for diagnosis and potential treatment 1

Important Caveats

• Proper ECG diagnosis is essential before treatment to distinguish SVT from ventricular tachycardia 2
• Calcium channel blockers and beta-blockers should be avoided in patients with suspected pre-excited AF, ventricular tachycardia, or systolic heart failure 2
• Patients with SVT should be educated on how to perform vagal maneuvers for ongoing management 1
• Untreated PSVT can lead to tachycardia-mediated cardiomyopathy in rare cases (1%) 4