# Baseline heart rate Z-score is associated with early RPP trajectory during dexmedetomidine–sufentanil sedation after pediatric transcatheter closure

## TL;DR

The study finds that a baseline heart rate Z-score is linked to early heart workload changes in children after heart procedures using specific sedation.

## Contribution

This study introduces the use of HR Z-score as a predictor of early RPP trajectory under DEX + SF sedation in pediatric patients.

## Key findings

- Baseline HR Z-score significantly modifies early postoperative RPP trajectory under DEX + SF sedation.
- HR changes drive RPP differences, while blood pressure changes are not significant.
- Bradycardia occurred in 9.4% of patients, but no hypotension was observed.

## Abstract

Dexmedetomidine (DEX) plus sufentanil (SF) sedation is commonly used after transcatheter closure for simple congenital heart disease (CHD), yet early hemodynamic responses vary. Absolute heart rate (HR) values are not comparable across pediatric ages; an age-standardized HR Z-score may better contextualize baseline HR status.

To evaluate the association between baseline HR Z-score and early postoperative trajectories of rate–pressure product (RPP), HR, and mean arterial pressure (MAP) under a standardized DEX + SF pathway, and to describe safety outcomes.

We retrospectively studied 96 children (0–16 years) admitted to the PICU after transcatheter closure (June 2023–August 2025). Hemodynamics were recorded at admission (T0), 1 h, 4 h, and 8 h. Longitudinal associations were assessed using linear mixed models including time, HR Z-score, and a time × Z-score interaction, with age as a covariate, with sensitivity analyses.

RPP decreased over time and showed a significant time × HR Z-score interaction, indicating that baseline HR Z-score modified the early postoperative RPP trajectory. The corresponding interaction was significant for HR but not for systolic blood pressure or MAP, consistent with HR-driven differences, while SBP/MAP interactions were not statistically significant in this cohort. Bradycardia occurred in 9/96 patients (9.4%), and no hypotension events were observed.

Baseline HR Z-score, as an approximate age-standardized index of heart rate, is associated with early postoperative myocardial workload trajectory after transcatheter closure under DEX + SF sedation, primarily via HR reduction, and may help guide monitoring intensity.