What is the management of supraventricular tachycardia (SVT)?

Management of Supraventricular Tachycardia (SVT)

The management of SVT should follow a stepwise approach starting with vagal maneuvers, followed by adenosine for acute termination, and considering catheter ablation as the definitive treatment for recurrent cases. 1

Acute Management of SVT

First-Line Approaches

• Vagal maneuvers should be attempted first in hemodynamically stable patients:

  • Valsalva maneuver: Have patient bear down against closed glottis for 10-30 seconds (equivalent to 30-40 mmHg) while in supine position 1
  • Carotid sinus massage: Apply steady pressure over right or left carotid sinus for 5-10 seconds after confirming absence of carotid bruit 1
  • Cold stimulus to face: Apply ice-cold wet towel to face (based on diving reflex) 1
  • Success rate of switching between techniques is approximately 27.7% 1

• Adenosine is recommended if vagal maneuvers fail:

  • Highly effective (90-95% success rate) for terminating SVT 1
  • Brief side effects (<1 minute) may occur in approximately 30% of patients 1
  • Caution: May precipitate atrial fibrillation; have equipment for cardioversion available 1

Second-Line Approaches for Stable Patients

• Intravenous calcium channel blockers (diltiazem or verapamil):

  • Effective for acute termination in hemodynamically stable patients 1
  • Contraindicated in patients with suspected ventricular tachycardia, pre-excited atrial fibrillation, or systolic heart failure 1

• Intravenous beta blockers:

  • Reasonable alternative though less effective than calcium channel blockers 1
  • Better safety profile in patients with contraindications to calcium channel blockers 1

For Hemodynamically Unstable Patients

• Synchronized cardioversion is indicated when:
  • Patient is hemodynamically unstable 1
  • Vagal maneuvers and adenosine are ineffective or contraindicated 1
  • Pharmacological therapy has failed 1

Special Considerations

Pre-excited AF (in WPW Syndrome)

• Synchronized cardioversion should be performed immediately in hemodynamically unstable patients 1
• For stable patients with pre-excited AF, ibutilide or intravenous procainamide are recommended 1
• Avoid AV nodal blocking agents (diltiazem, verapamil, beta blockers) in patients with suspected pre-excitation as they may enhance conduction over accessory pathway 1

Long-Term Management

Pharmacological Options

• Oral beta blockers, diltiazem, or verapamil are first-line for ongoing management in patients without pre-excitation 1

  • Effective in reducing episode frequency and duration 1

• Flecainide or propafenone may be used in patients without structural heart disease who are not candidates for ablation 1, 2

  • Contraindicated in patients with structural heart disease or ischemic heart disease due to proarrhythmic risk 2

• Sotalol may be considered in patients who cannot undergo ablation and when other agents are ineffective 1

Definitive Treatment

• Electrophysiological study with catheter ablation is recommended as first-line therapy for recurrent, symptomatic SVT 1, 3

  • High success rates (94-98.5%) with low complication rates 3
  • Provides potential cure without need for chronic medication 1

• Patient education on proper vagal maneuver technique for self-management during episodes 1

Pitfalls and Caveats

• Always confirm the diagnosis before treatment; distinguish SVT from ventricular tachycardia 1
• Avoid eyeball pressure as a vagal maneuver due to potential dangers 1
• In patients with pre-excitation, avoid AV nodal blocking agents (verapamil, diltiazem, beta blockers) as they may accelerate ventricular rate during atrial fibrillation 1
• Monitor for atrial or ventricular premature complexes after conversion that may trigger recurrence 1
• Flecainide can cause new or worsened arrhythmias, especially in patients with structural heart disease 2
• Consider tachycardia-mediated cardiomyopathy (occurs in ~1% of patients) in cases of persistent or frequent SVT 3