From the Guidelines
The most effective treatment for AVNRT is catheter ablation, which has a success rate of over 95% and a low complication risk, as recommended by the 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia 1. For acute termination of an AVNRT episode, the following steps can be taken:
- Vagal maneuvers like the Valsalva maneuver or carotid sinus massage should be attempted first, as they are quick and effective in terminating SVT, with a success rate of 27.7% 1.
- If vagal maneuvers fail, intravenous adenosine is the first-line medication, typically given as a 6 mg rapid bolus, followed by a 12 mg dose if needed, with a success rate of approximately 95% in terminating AVNRT 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) 1. For long-term management, the following options are available:
- Catheter ablation is the definitive treatment, with a success rate of over 95% and a low complication risk, as recommended by the 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia 1.
- If ablation is not feasible, chronic medications can be used, including beta-blockers (metoprolol 25-100 mg twice daily), calcium channel blockers (diltiazem 120-360 mg daily or verapamil 120-360 mg daily), or class IC antiarrhythmics like flecainide (50-150 mg twice daily) for patients without structural heart disease 1. It is essential to note that the treatment of AVNRT should prioritize the patient's quality of life, morbidity, and mortality, and the chosen treatment should be based on the individual patient's needs and medical history.
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 Flecainide acetate tablets, USP are indicated for the prevention of paroxysmal supraventricular tachycardias (PSVT), including atrioventricular nodal reentrant tachycardia (AVNRT). The treatment for AVNRT can include flecainide acetate tablets, USP, in patients without structural heart disease, for the prevention of PSVT associated with disabling symptoms 2.
From the Research
Treatment Options for AVNRT
- Acute termination of AVNRT can be achieved by vagal maneuvers or drugs such as adenosine compounds and calcium channel blockers 3
- For chronic therapy, digitalis, calcium blockers, and beta-blockers are effective and simple initial options 3
- Catheter ablation, especially using radiofrequency energy, is a therapeutic alternative for resistant patients, with a high success rate and low incidence of complications 3, 4
- Transvenous cryo-ablation of the slow pathway is also an option, with an acute success rate of 87% and a long-term clinical success rate of 85% 5
Medications Used for AVNRT
- Adenosine is effective in the acute setting, but may have negative short-term side effects such as flushing or chest discomfort 6, 7
- Calcium channel blockers (diltiazem or verapamil) can be used acutely or as long-term therapy, and are equally as efficacious as adenosine in converting AVNRT to sinus rhythm 6, 7
- Beta blockers (metoprolol) can be used acutely or as long-term therapy, but have lower efficacy than calcium channel blockers 6, 7
Catheter Ablation for AVNRT
- Catheter ablation has a success rate of 95% and recurrence rate of less than 5%, and causes inadvertent heart block in less than 1% of patients 6
- Radiofrequency ablation is becoming the therapy of first choice for the treatment of AVNRT due to its high success rate and low incidence of complications 3, 4
- Cryo-ablation is also an option, with a lower risk of permanent AV-block compared to radiofrequency ablation, but may have a higher recurrence rate 5