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This Article Full Text Full Text (PDF) All Versions of this Article: 294/2/H884    most recent 00318.2007v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Schäffer, L. Articles by Beinder, E. Search for Related Content PubMed PubMed Citation Articles by Schäffer, L. Articles by Beinder, E.

Cardiac autonomic balance in small-for-gestational-age neonates

Departments of ¹Obstetrics, ²Neonatology, and ³Pediatric Cardiology, University of Zürich, Zürich, Switzerland; and ⁴Department of Pediatrics, University of Erlangen, Erlangen, Germany

Submitted 14 March 2007 ; accepted in final form 30 November 2007

The cardiac sympathetic nervous system is one putative key factor involved in the intrauterine programming of adult cardiovascular disease. We therefore analyzed cardiac autonomic system activity in small for gestational age (SGA) neonates. Heart rate variability (HRV) from 24-h ECG recordings were analyzed for time-domain and frequency-domain parameters in 27 SGA neonates [median 261 (240–283) days of gestation] compared with 27 appropriate for gestational age (AGA) neonates [median 270 (239–293) days of gestation]. In addition, salivary -amylase levels were analyzed during resting conditions and in response to a pain-induced stress event in 18 SGA [median 266 (240–292) days of gestation] and 34 AGA [median 271 (240–294) days of gestation] neonates. Overall HRV was not significantly different in SGA neonates compared with AGA neonates (SD of all valid NN intervals: P = 0.14; triangular index: P = 0.29), and the sympathovagal balance [low frequency (LF)/high frequency (HF)] was similar (P = 0.62). Parameters mostly influenced by sympathetic activity did not reveal significant differences: (SD of the average of valid NN intervals: P = 0.27; average of the hourly means of SDs of all NN intervals: P = 0.66, LF: P = 0.83) as well as vagal tone-influenced parameters were unaltered (average of the hourly square root of the mean of the sum of the squares of differences between adjacent NN intervals: P = 0.59; proportion of pairs of adjacent NN intervals differing by >50 ms: P = 0.93; HF: P = 0.82). Median resting levels for -amylase were not significantly different in SGA neonates (P = 0.13), and a neonatal stress stimulus revealed similar stress response patterns (P = 0.29). HRV and salivary -amylase levels as indicators of cardiac autonomic activity were not altered in SGA neonates compared with AGA neonates. Thus, it appears that the intrauterine activation of the sympathetic system in SGA fetuses does not directly persist into postnatal life, and neonatal sympathovagal balance appears to be preserved.

intrauterine programming; cardiovascular; amylase; heart rate variability; sympathovagal balance