What are the medications used to treat Supraventricular Tachycardia (SVT)?

Medications for Supraventricular Tachycardia (SVT)

Adenosine is the first-line medication for acute treatment of SVT, with success rates of approximately 95% for terminating AVNRT and 90-95% for orthodromic AVRT. 1

Acute Management of SVT

First-Line Approaches

• Vagal maneuvers should be attempted first for acute treatment of regular SVT, with Valsalva maneuver being more successful than carotid sinus massage (overall success rate of 27.7% when both techniques are used) 1
• Adenosine (6mg IV rapid bolus, followed by up to two 12mg boluses if necessary) is recommended as first-line pharmacological therapy for acute treatment of SVT 1, 2
• Synchronized cardioversion should be performed immediately for hemodynamically unstable patients when vagal maneuvers and adenosine fail or are not feasible 1

Second-Line Medications for Hemodynamically Stable Patients

• Intravenous calcium channel blockers (diltiazem or verapamil) are particularly effective for acute termination of SVT with success rates of 64-98% 1
• Intravenous beta blockers can be used, though they have limited evidence for effectiveness compared to calcium channel blockers 1
• Oral beta blockers, diltiazem, or verapamil may be reasonable for acute treatment when IV access is unavailable 1

Refractory Cases

• Synchronized cardioversion is recommended when pharmacological therapy fails or is contraindicated in hemodynamically stable patients 1
• Intravenous amiodarone may be considered when other therapies are ineffective or contraindicated 1
• For pre-excited AF (in WPW syndrome), ibutilide or intravenous procainamide are beneficial in hemodynamically stable patients 1

Ongoing Management of SVT

First-Line Medications

• Oral verapamil or diltiazem are recommended for long-term management in patients who are not candidates for, or prefer not to undergo, catheter ablation 1
• Oral beta blockers are useful for ongoing management in patients with symptomatic SVT who do not have ventricular pre-excitation during sinus rhythm 1

Second-Line Medications

• Flecainide is reasonable for ongoing management in patients without structural heart disease who have symptomatic SVT and are not candidates for catheter ablation 1, 3
• Propafenone may be used under similar conditions as flecainide 1
• Sotalol may be reasonable for ongoing management in patients with symptomatic SVT who are not candidates for catheter ablation 1

Third-Line Medications

• Dofetilide may be reasonable when first and second-line agents are ineffective or contraindicated 1
• Oral amiodarone may be considered when all other options are ineffective or contraindicated 1
• Oral digoxin may be reasonable for ongoing management in patients without pre-excitation 1

Important Considerations and Precautions

• Calcium channel blockers (diltiazem, verapamil) should be avoided in:

  • Patients with ventricular tachycardia or pre-excited AF (can cause hemodynamic instability and ventricular fibrillation) 1
  • Patients with systolic heart failure 1

• Flecainide dosing considerations:

  • Starting dose is 50mg every 12 hours for PSVT and PAF patients 3
  • Dose may be increased in increments of 50mg bid every four days 3
  • Maximum recommended dose is 300mg/day for paroxysmal supraventricular arrhythmias 3
  • Should not be used in patients with structural heart disease or recent myocardial infarction 3

• Special patient populations:

  • Patients with impaired venous return to the right heart (e.g., pulmonary hypertension) may require higher-than-recommended doses of adenosine 4
  • Pediatric patients require specialized dosing under direct supervision of a pediatric cardiologist 3

• All patients treated for SVT should be referred for heart rhythm specialist evaluation for consideration of definitive treatment with catheter ablation 5