Adenosine for Supraventricular Tachycardia

Introduction to Adenosine Therapy

The American Heart Association recommends adenosine as the first-line pharmacologic treatment for supraventricular tachycardia (SVT) in infants when vagal maneuvers fail, with a success rate of 90-95% in pediatric patients 2
Adenosine is the definitive first-line pharmacologic treatment for SVT in infants when vagal maneuvers fail, according to the ACC/AHA/HRS guidelines 1, 2, 3

Adenosine briefly depresses AV node conduction, terminating reentrant tachycardias that involve the AV node (AVNRT and orthodromic AVRT) in 85-100% of cases, as reported by the Journal of the American College of Cardiology 4
The American College of Cardiology states that adenosine has an extremely short half-life, making it safe even if ineffective, although the exact half-life is not specified in this context 4

The initial dose of adenosine for infants is 0.05 mg/kg IV rapid bolus, which can be increased in increments of 0.05 mg/kg every 1-2 minutes up to a maximum of 0.25 mg/kg, as recommended by the American Heart Association 1, 3
Adenosine must be given as a rapid IV push followed immediately by a 20 mL saline flush through a large proximal vein, according to the Circulation journal 1, 3
A defibrillator should be readily available during adenosine administration, as stated by the American College of Cardiology 2, 3

The American Heart Association recommends that calcium channel blockers like diltiazem are not used for infants and young children due to the risk of severe hypotension and cardiac arrest 1
Beta blockers are second-line agents for pediatric SVT, used only when adenosine is ineffective or contraindicated, as reported by the Circulation journal 1
Amiodarone is indicated for atrial fibrillation or when other agents fail, not as initial therapy for regular narrow-complex SVT, according to the American College of Cardiology 1

Continuous ECG monitoring is required during and after adenosine administration, as recommended by the Praxis Medical Insights 3, 5
The American Heart Association states that monitoring of blood pressure, respiratory status, and capillary refill is necessary during adenosine administration 3
Recurrence of SVT is common due to adenosine's short half-life, and patients should be watched for recurrence, as reported by the Praxis Medical Insights 3, 5

Flushing, dyspnea, and chest discomfort occur in approximately 30% of patients but last less than 1 minute, as stated by the Circulation journal 2

Asthma is a contraindication for adenosine due to the risk of bronchospasm, as reported by the American Heart Association 1, 3
Second or third-degree AV block or sick sinus syndrome are contraindications for adenosine, according to the Praxis Medical Insights 3

If SVT recurs after successful adenosine conversion, repeat adenosine dosing or consider a longer-acting AV nodal blocking agent such as a beta blocker, as recommended by the Praxis Medical Insights 3, 5
Patients should be monitored for at least 1-2 hours after successful conversion, as stated by the Praxis Medical Insights 5
Recurrent episodes may require prophylactic antiarrhythmic therapy or cardiology referral, according to the Praxis Medical Insights 5
If adenosine repeatedly fails, synchronized cardioversion should be performed, as recommended by the Circulation journal 2, 6