Effect of adenosine on retrograde AV node conduction in pediatric and young adult patients

Abstract

Background

Adenosine is used as a diagnostic tool during electrophysiology studies to transiently block atrioventricular node (AVN) conduction. Persistence of VA conduction after adenosine administration is often interpreted as evidence of accessory pathway conduction. Studies in adults have shown that adenosine effect on retrograde AVN conduction is heterogeneous and there may be differing responses in those with dual AVN physiology.

Objectives

Our objective was to evaluate these phenomena in pediatric patients. Specifically, our goal was to assess retrograde AVN response to adenosine in pediatric patients.

Methods

We evaluated retrograde AVN response to adenosine in pediatric patients undergoing an electrophysiology study for supraventricular tachycardia or ventricular pre-excitation. Patients aged 4–25 years received intravenous adenosine (0.2 mg/kg, maximum 18 mg) during ventricular overdrive pacing.

Results

Of 58 analyzed patients, 30 had dual AVN physiology. Adenosine administration resulted in complete retrograde AVN block in 50% of patients with dual AVN physiology, compared to 82% of those without dual AVN physiology (p = 0.01).

Conclusion

In children, continued retrograde AVN conduction after adenosine does not reliably indicate accessory pathway presence and does not rule out dual AVN physiology as the mechanism of tachycardia.