When to treat Atrioventricular Nodal Reentrant Tachycardia (AVNRT)?

From the Guidelines

Treatment for Atrioventricular Nodal Reentrant Tachycardia (AVNRT) should be initiated when patients experience symptomatic episodes or have recurrent episodes that significantly impact quality of life.

Key Considerations

• Acute management of AVNRT involves vagal maneuvers like the Valsalva maneuver or carotid sinus massage as first-line interventions, as recommended by 1 and 1.
• If these fail, intravenous adenosine (6 mg rapid bolus, followed by 12 mg if needed) is the drug of choice for acute termination due to its brief AV nodal blockade, as supported by 1 and 1.
• Alternative medications include calcium channel blockers like verapamil (5-10 mg IV) or diltiazem (0.25 mg/kg IV), or beta-blockers such as metoprolol (5 mg IV), as suggested by 1 and 1.

Long-term Management

• For long-term management, catheter ablation is the definitive treatment with over 95% success rate and low complication risk, as stated in 1.
• If ablation is not feasible, chronic pharmacologic therapy options include beta-blockers (metoprolol 25-100 mg twice daily), calcium channel blockers (diltiazem 120-360 mg daily or verapamil 120-480 mg daily), or class IC antiarrhythmics like flecainide (50-200 mg twice daily) for patients without structural heart disease, as recommended by 1.

Rationale

Treatment is necessary because AVNRT, while typically not life-threatening, can cause significant symptoms including palpitations, dizziness, shortness of breath, and rarely syncope due to its mechanism involving a reentrant circuit within or near the AV node causing rapid heart rates of 140-250 beats per minute.

Additional Options

• Clinical follow-up without pharmacological therapy or ablation may be reasonable for ongoing management in minimally symptomatic patients with AVNRT, as suggested by 1.
• Oral beta blockers, diltiazem, or verapamil may be reasonable for acute treatment in hemodynamically stable patients with AVNRT, as stated in 1.

From the FDA Drug Label

In patients without structural heart disease, flecainide acetate tablets, USP are indicated for the prevention of: •paroxysmal supraventricular tachycardias (PSVT), including atrioventricular nodal reentrant tachycardia, atrioventricular reentrant tachycardia and other supraventricular tachycardias of unspecified mechanism associated with disabling symptoms

Treatment of AVNRT should be considered when symptoms are disabling. The decision to treat should be based on the presence of disabling symptoms associated with the arrhythmia, as indicated in the drug label 2.

From the Research

When to Treat AVNRT

The decision to treat Atrioventricular Nodal Reentrant Tachycardia (AVNRT) depends on several factors, including the frequency and severity of symptoms, the impact on quality of life, and the presence of underlying heart disease.

• Treatment is usually considered when AVNRT episodes are frequent, prolonged, or cause significant symptoms such as palpitations, shortness of breath, or chest pain 3, 4.
• In patients with hemodynamic collapse or severe symptoms, treatment is mandatory 4.
• For patients with infrequent or mild symptoms, treatment may not be necessary, and a watchful waiting approach may be adopted 5.
• Catheter ablation is a highly effective treatment for AVNRT and can be considered early in the treatment process, especially in patients with frequent or severe symptoms 4, 5.

Treatment Options

The treatment options for AVNRT include:

• Medications such as adenosine, verapamil, and beta-blockers to control symptoms and prevent episodes 3, 6.
• Catheter ablation to destroy the abnormal electrical pathway in the heart 4, 5.
• In some cases, pacemaker implantation may be necessary if catheter ablation causes atrioventricular block 4.

Special Considerations

• In children, pharmacologic management is often recommended, and catheter ablation is usually reserved for older children with frequent AVRT 6.
• In patients with underlying heart disease, treatment should be individualized, and catheter ablation may be considered earlier in the treatment process 4, 5.
• A simple clinical score based on age categories and atrial fibrillation history can efficiently predict the risk of symptom recurrence due to atrial arrhythmias and inappropriate sinus tachycardia 7.