From the Guidelines
AVNRT (Atrioventricular Nodal Reentrant Tachycardia) is a common type of supraventricular tachycardia that can be diagnosed with ECG, Holter monitoring, event recorders, and electrophysiology studies, and treated with vagal maneuvers, medications like adenosine, beta-blockers, or calcium channel blockers, and catheter ablation, which is highly effective with a 95% success rate, as recommended by the 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia 1.
Diagnosis of AVNRT
Diagnosis of AVNRT typically involves:
- ECG during an episode showing a narrow-complex tachycardia with heart rates of 140-250 beats per minute
- Absent P waves or retrograde P waves hidden in the QRS complex
- Holter monitoring or event recorders to capture episodes
- Electrophysiology studies to confirm the diagnosis
Treatment of AVNRT
Treatment options for AVNRT include:
- Vagal maneuvers like the Valsalva maneuver as first-line intervention during episodes
- Medications such as:
- Adenosine (6-12 mg IV) to terminate acute episodes
- Beta-blockers (e.g. metoprolol 25-100 mg twice daily) to prevent recurrences
- Calcium channel blockers (e.g. diltiazem 120-360 mg daily) to prevent recurrences
- Catheter ablation, which is highly effective with a 95% success rate, as recommended by the 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia 1
Long-term Management of AVNRT
For long-term management, catheter ablation is recommended in patients with AVNRT, as it is potentially curative and chronic pharmacological therapy is usually not needed after the procedure, with a success rate of >95% and a <1% risk of AV block, as stated in the 2015 ACC/AHA/HRS guideline 1. Alternatively, oral medications such as:
- Beta-blockers (e.g. metoprolol 25-100 mg twice daily)
- Calcium channel blockers (e.g. diltiazem 120-360 mg daily)
- Flecainide or propafenone (for patients without structural heart disease or ischemic heart disease) may be used to prevent recurrences.
Living with AVNRT
Living with AVNRT involves:
- Recognizing triggers like caffeine, alcohol, and stress
- Maintaining regular follow-ups with a cardiologist
- Possibly carrying medication for acute episodes
- Informing healthcare providers about the condition before surgeries or when starting new medications to avoid potential interactions or complications.
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
AVNRT Definition and Diagnosis: AVNRT stands for Atrioventricular Nodal Reentrant Tachycardia, a type of supraventricular tachycardia. Diagnosis of AVNRT is typically made through:
- Electrocardiogram (ECG) to show the characteristic pattern of AVNRT
- Holter monitoring or event monitoring to capture episodes of tachycardia
- Electrophysiology study to confirm the diagnosis and identify the reentrant circuit
Treatment and Maintenance: Treatment options for AVNRT include:
- Vagal maneuvers: techniques to stimulate the vagus nerve and slow down the heart rate
- Medications: such as flecainide acetate tablets, USP 2 or verapamil 3 to prevent or terminate episodes of tachycardia
- Catheter ablation: a procedure to destroy the abnormal electrical pathway in the heart Maintenance therapy may involve:
- Long-term medication: to prevent episodes of tachycardia
- Regular monitoring: to check for any changes in the heart rhythm or symptoms
- Lifestyle modifications: such as avoiding triggers that can cause episodes of tachycardia
From the Research
What is AVNRT
- Atrioventricular-nodal-reentry tachycardia (AVNRT) is a form of supraventricular tachycardia (SVT) that is relatively common in the emergency department (ED) 4
- It is rarely indicative of underlying electrical or structural pathology 4
- AVNRT is caused by reentry phenomena or automaticity at or above the atrioventricular node, and includes atrioventricular nodal reentrant tachycardia, atrioventricular reciprocating tachycardia, and atrial tachycardia 5
Diagnosis of AVNRT
- The history is important to elicit episodic symptoms because physical examination and electrocardiography findings may be normal 5
- A Holter monitor or event recorder may be needed to confirm the diagnosis 5
- The diagnosis of AVNRT can be made by evaluating the patient's symptoms, medical history, and electrocardiogram (ECG) results 4
Treatment of AVNRT
- Vagal maneuvers, such as the Valsalva maneuver or carotid sinus massage, may terminate the arrhythmia 5, 4, 6, 7, 8
- Adenosine is effective in the acute setting, but may cause severe discomfort 5, 4
- Calcium channel blockers (diltiazem or verapamil) or beta blockers (metoprolol) can be used acutely or as long-term therapy 5, 4
- Class Ic antiarrhythmics (flecainide or propafenone) can be used long-term 5
- 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 5
Maintenance and Living with AVNRT
- Most patients with AVNRT may be discharged with appropriate follow-up 4
- Patients with AVNRT should be educated on how to recognize and manage their symptoms, and when to seek medical attention 4
- Long-term management of AVNRT may involve the use of medications, such as calcium channel blockers or beta blockers, to prevent recurrences 5, 4
- Patients with AVNRT should be followed up regularly by a cardiologist to monitor their condition and adjust their treatment plan as needed 5, 4