Atrioventricular Nodal Reentrant Tachycardia (AVNRT) Treatment and Management

Etiology and Pathophysiology

The anatomic substrate of AVNRT is dual AV nodal physiology, which consists of two distinct pathways within the AV node region 1, 2

AVNRT typically presents with sudden onset of palpitations, often described as "pounding in the neck" 3, 1
Possible shortness of breath, dizziness, and neck pulsations 1
Syncope is rare 1
Heart rates typically between 180-200 bpm (range 110-250 bpm) 2
May occur spontaneously or be provoked by exertion, caffeine, tea, or alcohol 3

The American Heart Association recommends vagal maneuvers as first-line treatment for hemodynamically stable patients (Class I recommendation) 3, 4
Adenosine IV is recommended as second-line treatment for hemodynamically stable patients (Class I recommendation) 3, 4
IV calcium channel blockers (diltiazem or verapamil) or beta blockers are recommended as third-line treatment for hemodynamically stable patients (Class IIa recommendation) 3, 4
Immediate synchronized cardioversion is recommended for hemodynamically unstable patients (Class I recommendation) 3, 4

Catheter ablation of the slow pathway is recommended as first-line definitive treatment for AVNRT (Class I recommendation) 5
Oral verapamil or diltiazem are recommended as alternative pharmacological options for patients who do not prefer ablation (Class I recommendation) 5
Oral beta blockers are recommended as alternative pharmacological options for patients who do not prefer ablation (Class I recommendation) 5

The American College of Cardiology recommends ensuring the rhythm is truly AVNRT before treatment, as verapamil or diltiazem can be dangerous in VT or pre-excited AF 3
Beta blockers should be avoided in patients with severe conduction abnormalities or sinus node dysfunction 1

The American College of Cardiology recommends performing immediate synchronized cardioversion as the definitive treatment when a patient with AVNRT demonstrates hemodynamic instability, with a Class I recommendation and the highest priority 6, 7, 8
Vagal maneuvers can be attempted first if immediately feasible and the patient remains conscious, but do not delay cardioversion if the patient is truly unstable, as recommended by the American Heart Association 6, 8
Adenosine IV may be considered if immediately available and can be administered within seconds, but again, do not delay cardioversion for drug preparation if the patient is deteriorating, according to the American College of Cardiology 6, 8

The American College of Cardiology defines hemodynamic instability as hypotension with altered mental status, signs of shock, acute heart failure or pulmonary edema, or ongoing chest pain suggesting ischemia 6, 7

The American Heart Association advises avoiding IV calcium channel blockers (verapamil, diltiazem) in hemodynamically unstable patients, as these are only reasonable for stable patients 6, 7, 8
The American College of Cardiology recommends avoiding IV beta blockers in unstable patients, as these can worsen hypotension and cause further hemodynamic deterioration 6, 7

The American Heart Association suggests evaluating the patient for definitive management with catheter ablation once stabilized 6, 8

The recommendation for immediate cardioversion in hemodynamically unstable AVNRT carries a Class I, Level of Evidence B-NR designation from the 2015 ACC/AHA/HRS guidelines, representing the strongest possible recommendation 6, 7, 8