Atrioventricular Nodal Reentry Tachycardia Treatment & Management

Updated: Dec 27, 2017
  • Author: Brian Olshansky, MD; Chief Editor: Jose M Dizon, MD  more...
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Treatment

Approach Considerations

Rest, reassurance, sedation, and/or vagal maneuvers may terminate an attack of atrioventricular nodal reentry tachycardia (AVNRT). The successful management of an acute attack, however, depends on the symptoms, the presence of underlying heart disease, and the natural history of previous episodes.

In the presence of a wide-complex tachycardia, the institution of therapy should always follow a careful review of the patient's prior cardiac history, including left ventricular function and previous electrocardiograms (ECGs), which are helpful tools for defining the origin of the arrhythmia (ie, supraventricular vs ventricular).

The use of calcium channel blockers is contraindicated in patients with tachycardias of ventricular origin and may cause hemodynamic compromise and death.

Vagal maneuvers

To terminate AVNRT, try vagal maneuvers (eg, carotid sinus massage, exposure of the face to ice water, Valsalva maneuver) before initiating drug treatment. These maneuvers can also be tried after each pharmacologic 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.

Direct-current synchronized cardioversion

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. However, DC cardioversion is rarely necessary for AVNRT.

Competitive atrial or ventricular pacing may be used if DC cardioversion is contraindicated (eg, if high doses of digitalis have been administered).

Diet

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.

Activity

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

Consultations

Consultations include the following:

  • Cardiologist

  • Electrophysiologist

Transfer

Transfer to a facility capable of performing electrophysiologic studies and radiofrequency ablation may be needed.

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Pharmacologic Therapy

Drugs that can be used to terminate an attack include adenosine, calcium channel blockers (eg, diltiazem, verapamil), beta-blockers, and digitalis.

Adenosine

Adenosine is the first-line drug used for termination of atrioventricular nodal reentry tachycardia (AVNRT). It is a potent purinergic blocker and generally blocks activation preferentially in the “slow pathway” of the AVNRT reentry circuit. In rare cases, the administration of adenosine may lead to atrial fibrillation or even asystole for a short period.

Adenosine administration should be given through a central, large bore intravenous (IV) needle, 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. The initial dose is 6 mg followed by 12 mg and occasionally 18 mg. It should not be used in heart transplantation patients, it may be ineffective if given to a patient taking theophylline, and it may be potentiated by dipyridamole.

A 2017 emergency medicine review suggests that nondihydropyridine calcium channel blockers such as diltiazem and verapamil may be as effective as adenosine for converting narrow-complex tachycardia, particularly for refractory states, to sinus rhythm, and that no statistically significant difference exists in the conversion rate between these agents and adenosine (>90% conversion rate for both drug groups) (although adenosine is rapid acting). [3] However, adenosine is associated with more negative short-term side effects. Hemodynamically unstable patients should undergo electrical cardioversion. [3]

Preventive therapy

Preventive therapy is needed for frequent, prolonged, or highly symptomatic episodes that do not terminate spontaneously or for 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.

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Radiofrequency Catheter Ablation

Radiofrequency catheter ablation [9] 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.

Radiofrequency catheter ablation is associated with cure rates of greater than 95%, with very low risk of atrioventricular (AV) block (<1%) for patients with AV nodal reentry tachycardia (AVNRT). [9] This 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, with radiofrequency energy delivered via the catheter to interrupt conduction via this pathway and thus eliminate the circuit.

A retrospective study of 153 patients who underwent ablation of the slow pathway in AVNRT indicated that the interval between the atrial electrogram in the His-bundle position and the distal ablation catheter [A(H)-A(RFd)] and the proximal coronary sinus catheter [A(RFd)-A(CS)] before radiofrequency ablation may be used as electrophysiologic markers for predicting the occurrence of junctional beats and impending AV block. [10]

Cryoablation

Cryoablation has been increasingly used for treating AVNRT, with reported safety and efficacy, [11] including in children. [12, 13] One review of the literature concluded that cryoablation is safe and effective for AVNRT and is an option in patients for whom the avoidance of AV block is a priority, such as children and young adults. [12]  A more recent study also found cryoablation to be effective for 125 children with AVNRT (age >10 years), with comparable acute and mid-term follow-up success rates for both 6-mm and 8-mm tip catheters. [13]

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