Preoperative Heart Rate Variability and Parasympathetic Modulation in Newborns with Transposition of the Great...

We retrospectively assessed preoperative cardiac autonomic regulation in neonates with TGA who subsequently underwent arterial switch operation.

Neonates treated between 1 January and 31 December 2024 were studied. Heart rate variability was derived from continuous ECG recordings, with low-frequency and high-frequency spectral components calculated from RR intervals. Longitudinal associations between HRV indices and the interval to surgery were evaluated using linear mixed-effects models with adjustment for relevant clinical covariates.

Twenty neonates were included. The median age at ASO was 7 days (IQR 5-9), median weight was 3100 g (IQR 2900-3400), and median preoperative oxygen saturation was 76% (IQR 70-82%). Balloon atrial septostomy had been performed in 10 patients. HRV data represented 150 patient-days of monitoring. In unadjusted analyses, both LF and HF power declined as surgery was delayed, with the strongest association observed for HF power. In the adjusted mixed-effects model, longer time to surgery remained independently associated with lower HF power (β = -0.07, 95% CI -0.129 to -0.011, p = 0.03).

Serial HF measurements may reflect progressive changes in autonomic regulation during the preoperative period in neonates with TGA.