Submitted on September 17, 2008
Revised on December 31, 2008
Accepted on January 5, 2009
Impairment of the Autonomic Nervous Function during Decompression Sickness in Swine
Yan Bai1, Richard Mahon2, Joseph White3, Peter Brink4, and Ki H. Chon5*
1 SUNY Stony Brook
2 Uniformed Services University
3 SUNY at Stony Brook
4 SUNY Health Science Center at Stony Brook
5 SUNY - Stony Brook
* To whom correspondence should be addressed. E-mail: ki.chon{at}sunysb.edu.
Dysautonomia has been observed in many cardiac diseases, however, its effect in decompression sickness (DCS) has not been well examined largely due to difficulty in obtaining experimental data in human or animal subjects. In this study, we examine how DCS affects the autonomic nervous system's (ANS) dynamics in swine. Baseline and post-DCS electrocardiograms were obtained via telemetry recordings and compared. These data were analyzed using both the power spectrum method and our recently-developed principal dynamic mode (PDM) analysis. PDM is able to separate the dynamic tones of the sympathetic and parasympathetic nervous. Both methods demonstrated a statistically significant decrease (> 55%, P<0.05) in the dynamics of both branches of the autonomic nervous systems in the swine with DCS when compared to the control condition. In cardiac diseases such as myocardial infarction, ANS imbalance is often associated with a significant increase in sympathetic tone which may or may not be counter-balanced by parasympathetic nervous activity. However, the effect of DCS is such that both branches of the ANS are depressed > 55% as compared to the control condition, suggesting impairment, but not imbalance of the ANS.
