A group of 10 consecutive infants (5 < 1 year and 5 > 1 year) presenting with nvH1N1 infection was evaluated with heart rate variability (HRV) and spontaneous baroreflex (SBR) through a recording during a 15-minute period of quiet sleep as well as 24 h holter monitoring. The same recordings were performed in 10 control subjects, paired for gestational and postnatal age. HRV sympathetic and parasympathetic (VLF, LF and HF) indices were obtained using spectral-domain analysis, and spontaneous baroreflex sensitivity (SBR) using simultaneous non-invasive continuous measure of arterial pressure and heart rate.
The group of infants less than 1 year had similar value as control group. Conversely, the group of infants more than 1 year showed significant lower spectral total power values (Ptot: 3347 vs. 5926 ms2/Hz, p < 0.1) and significant lower VLF, LF and HF indices (all p < 0.05) than the control group.
nvH1N1 infection in child could be associated with severe central autonomic dysfunction. Due to potential severe consequences, a systematic evaluation of autonomic regulation should be performed in order to avoid dramatic events.