What are the treatment options for Atrioventricular Nodal Reentrant Tachycardia (AVNRT)?

From the Guidelines

Treatment for Atrioventricular Nodal Reentrant Tachycardia (AVNRT) should start with vagal maneuvers, and if unsuccessful, intravenous adenosine is recommended as the first-line medication. According to the 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia 1, vagal maneuvers such as the Valsalva maneuver or carotid sinus massage can be attempted first to terminate the arrhythmia. If these maneuvers fail, intravenous adenosine is the next step, typically given as a 6 mg rapid bolus, followed by a 12 mg dose if needed 1.

Acute Management

For acute episodes of AVNRT, the following options are considered:

• Vagal maneuvers: The Valsalva maneuver or carotid sinus massage can be performed quickly and should be the first-line intervention to terminate SVT 1.
• Adenosine: Intravenous adenosine can be considered as both a therapeutic and diagnostic agent in narrow-complex tachyarrhythmias, terminating AVNRT in approximately 95% of patients 1.
• Calcium channel blockers: Verapamil (5-10 mg IV) or diltiazem (0.25 mg/kg IV) can be used as alternative medications 1.
• Beta-blockers: Such as metoprolol (5 mg IV) can also be considered for acute management 1.

Long-term Management

For long-term management, the following options are available:

• Catheter ablation is the definitive treatment with a success rate over 95% and low complication risk 1. This procedure modifies the slow pathway of the AV node to prevent reentry circuits.
• Chronic medications: Include beta-blockers (metoprolol 25-100 mg twice daily), calcium channel blockers (verapamil 120-360 mg daily or diltiazem 120-360 mg daily), or occasionally class IC antiarrhythmics like flecainide 1.
• Patient education: Patients should be educated about recognizing symptoms and performing vagal maneuvers at home for occasional episodes 1.

It's essential to note that the choice of treatment depends on the individual patient's condition, symptoms, and preferences. The guidelines recommend a personalized approach to managing AVNRT, considering the patient's specific needs and circumstances 1.

From the FDA Drug Label

Adenosine injection is indicated for the treatment of supraventricular tachycardia, including atrioventricular nodal reentrant tachycardia (AVNRT) 2. The recommended dose of adenosine for AVNRT is 6-12 mg administered as a rapid intravenous bolus [not explicitly stated in the provided labels, but generally recommended in clinical practice]. Verapamil, a calcium channel blocker, can also be used to treat AVNRT, but it is not the first-line treatment 3.

Treatment options for AVNRT:

• Adenosine injection: 6-12 mg IV bolus
• Verapamil (PO): may be used in some cases, but not as a first-line treatment Key considerations:
• Adenosine injection can cause significant hypotension, bronchoconstriction, and cardiac arrest, and should be used with caution in patients with certain medical conditions 2.
• Verapamil can cause hypotension, AV block, and cardiac arrest, and should be used with caution in patients with certain medical conditions 3.

From the Research

Treatment Options for Atrioventricular Nodal Reentrant Tachycardia (AVNRT)

The treatment options for AVNRT can be categorized into several approaches, including pharmacological therapy, catheter ablation, and vagal maneuvers.

• Pharmacological Therapy:

  • Adenosine is often used as the first-line treatment for acute AVNRT episodes, with a conversion rate of approximately 90% 4, 5, 6.
  • Verapamil and diltiazem, nondihydropyridine calcium channel blockers, are also effective in converting AVNRT to sinus rhythm, with fewer side effects compared to adenosine 6.
  • Beta-blockers, such as digoxin, can be used for long-term prevention of AVNRT episodes, especially when combined with other antiarrhythmic drugs 4, 5.
  • Class IC antiarrhythmic drugs, like flecainide and propafenone, and class IA drugs, such as procainamide, can also be used to terminate reentry tachycardia 4, 5.

• Catheter Ablation:

  • This approach is considered the therapy of choice for symptomatic AVNRT, with a high success rate and low risk of complications 7.
  • Conventional slow pathway ablation is effective for both typical and atypical AVNRT, with no significant difference in outcomes between the two forms 7.

• Vagal Maneuvers:

  • These maneuvers, such as carotid sinus massage and Valsalva maneuver, can increase vagal tone and help terminate AVNRT episodes 6, 8.
  • Vagal maneuvers are often used as the initial treatment approach, especially in hemodynamically stable patients 6, 8.

• Electrical Cardioversion:

  • This approach is reserved for hemodynamically unstable patients with AVNRT, and is considered the treatment of choice in such cases 6, 8.