Hemodynamic and Respiratory Effects of Regadenoson During Radiologic Imaging in Infants and Children

BACKGROUND: Myocardial perfusion imaging using radionuclides is a well-validated, noninvasive method to aid in the diagnosis of patients with suspected or known myocardial ischemia. To increase the sensitivity of the technique, pharmacologic agents which induce coronary vasodilatation are administered. Regadenoson is a novel selective A2A receptor agonist that has similar efficacy to adenosine for cardiac magnetic resonance imaging (MRI) with a more favorable adverse effect profile and is the most widely used pharmacologic stress agent. While widely used in adults, there is limited experience with it in pediatrics, particularly young children. METHODS: The current study retrospectively reviews our experience with stress cardiac MRI using regadenoson in children requiring general anesthesia. The study cohort included eight patients, all male, ranging in age from 2 to 6.2 years (mean age of 4.2 years) and in weight from 10 to 30.5 kg (mean weight of 18.5 kg). All patients received general anesthesia with endotracheal intubation and a volatile anesthetic agent. RESULTS: Heart rate 1 min prior to regadenoson was 99 ± 19.2 (mean ± standard deviation (SD)) beats per minute. Peak heart rate was achieved at an average of 4 min post regadenoson administration with a mean heart rate of 122 ± 15 beats per minute. The average of the mean arterial pressure 1 min prior to regadenoson was 53.4 ± 5.2 mm Hg. Mean arterial pressure nadir was noted at 6 min post regadenoson with a value of 44.1 ± 6.3 mm Hg. Blood pressure support with phenylephrine was required in four of the eight (50%) of patients. No adverse respiratory events were noted. Only one of the eight (13%) patients had a perfusion defect but had preserved ventricular function and recovered without incident. CONCLUSIONS: Use of regadenoson in pediatric patients requiring general anesthesia is safe and feasible.