Pediheart Podcast #386: What Is The "Right" Starting Dose Of Adenosine For SVT In Children?

The authors begin their work by reviewing how SVT is the most common arrhythmia in kids, affecting between 1 in 250 and 1 in 1,000 children, and how the first episode occurs in the first year of life in about 50% of children who have SVT.

They then review how intravenous adenosine blocks the AV node transiently and is recommended as first-line therapy for SVT because it works fast, has a short half-life, and is a safe agent with now many decades of experience.

Finally, it can sometimes unmask atrial arrhythmias.

For all these reasons, it is a very commonly used agent and is of great importance, obviously, in our field.

The authors then explain that the optimal first dose to effectively terminate SVT is not well established, and they note that inability to stop SVT on a first push of adenosine can delay cardioversion and lengthen a period of hemodynamic instability, and the result may be a need for multiple doses, and so they suggest that it's time we looked at this question of what dose can most commonly, safely, and successfully terminate SVT in hopes of avoiding delays in termination of SVT.

They mention that it is not known if adenosine is more or less effective in different forms of SVT, such as patients with WPW.

With this as a background, the authors state, and I quote, To address this gap, we conducted a systematic review and three-level meta-analysis of pediatric studies evaluating weight-based adenosine dosing and cardioversion success across electrophysiologic classifications.

This study was a systematic review and meta-analysis designed to determine whether adenosine dose influences the likelihood of terminating pediatric SVT.

And as usual, I would direct the listener to read the paper, particularly the second and third pages, to understand the complex methodology.

But in broad terms, the authors searched the literature through July 2025 and identified nine observational studies that included 480 children and 1,369 individual adenosine administrations.

Rather than analyzing outcomes only at the patient level, they examined the success of each adenosine bolus and grouped doses into weight-based categories to assess the relationship between dose and cardioversion success.

They then performed a meta-regression analysis to quantify how changes in dose affected the odds of conversion.

Overall, the methodology allowed the investigators to evaluate whether a dose-response relationship exists across a broad pediatric SVT population, despite the absence of randomized clinical trials.

And on to the results.