Atrioventricular Nodal Reentry Tachycardia (AVNRT) Treatment & Management

Management of an acute attack depends on the symptoms, the presence of underlying heart disease, and the natural history of previous episodes.

• Rest, reassurance, and sedation may terminate the attack.
• To terminate the tachycardia, try vagal maneuvers (eg, carotid sinus massage, exposure of the face to ice water, Valsalva maneuver) before initiating drug treatment. These maneuvers could also be tried after each pharmacological approach. Vagal maneuvers are unlikely to work and should not be tried if hypotension is present. Sometimes, putting the patient in the Trendelenburg position facilitates termination with a vagal maneuver.
• Drugs that can be used to terminate an attack include adenosine, calcium channel blockers (eg, diltiazem, verapamil), beta-blockers, and digitalis.

  • Adenosine is typically the first-line agent used for rapid termination of AVNRT. In rare cases, the administration of adenosine, as well as other AV nodal blocking agents, may lead to ventricular fibrillation or even asystole for a short period of time. The mechanism by which adenosine could cause ventricular fibrillation would generally be due to transient block in the AV node and rapid antegrade conduction through an accessory pathway, should one exist. This almost never occurs and would only occur in the presence of atrial fibrillation. Defibrillation equipment must be readily available when adenosine is administered. For AVNRT, if present, adenosine will never initiate ventricular fibrillation in standard doses.
  • Adenosine administration should be given through a central large bore IV as it has a very short half-life. It should be followed by a saline flush and elevation of the extremity in which it is being injected.
  • Adenosine is the drug of choice for rapid termination of AVNRT. Rarely, administration of adenosine (and other agents capable of blocking the AV node) has been associated with the induction of ventricular fibrillation. Equipment for defibrillation should be available when adenosine is administered.
• Direct current (DC) synchronized cardioversion is used to terminate an attack if the patient has hemodynamic compromise or if drug conversion fails and the patient continues to be symptomatic. DC cardioversion is rarely necessary for atrioventricular nodal reentry tachycardia (AVNRT).
• Competitive atrial or ventricular pacing may be used if DC cardioversion is contraindicated (eg, if high doses of digitalis have been administered).
• Preventive therapy is needed for frequent, prolonged, or highly symptomatic episodes that do not terminate spontaneously or those that cannot be easily terminated by the patient. Drugs that are used for prevention of recurrence include long-acting beta-blockers, calcium channel blockers, and digitalis. Radiofrequency catheter ablation^[1] of the reentrant circuit should be considered in patients who have frequent or highly symptomatic episodes, who do not want drug therapy, who cannot tolerate the drugs, or in whom drug therapy fails.

No surgical procedure is indicated, but radiofrequency catheter ablation is associated with cure rates of greater than 95% with very low risk of atrioventricular block (< 1%) for patients with AVNRT.^[1] Radiofrequency ablation is an invasive procedure in which catheter electrodes are placed percutaneously via central veins into the heart. Tachycardia can be initiated by pacing and by programmed electrical stimulation delivered from the atria or the ventricles. An ablation catheter electrode can be placed in the location of the slow AV nodal pathway and radiofrequency energy is delivered via the catheter to interrupt conduction via this pathway and thus eliminating the circuit.

• Cardiologist
• Electrophysiologist

No specific recommendations or restrictions are necessary, but some patients' episodes are exacerbated by caffeine, theophylline, or theobromine in selected foods (coffee, tea, or chocolate, respectively). Alcohol may also be a trigger.

Advise the patient to rest during tachycardia, preferably in a supine position.