Comprehensive assessment of autonomic dysfunction in patients with asthma using the regulatory systems activity index.

The regulatory systems activity index (RSAI), proposed by RM Bayevsky, can be used as an integral measure of the functional stress of the autonomic nervous system in patients with asthma. RSAI values of 8-10 should be used as a criteria for maladaptive and prognostically unfavorable course of asthma. Autonomic dysfunction at these RSAI levels is characterized by a pronounced reduction in total power of the spectrum of heart rate variability (HRV) (TP<1000ms), significant predominance of humoral-metabolic waves (VLF> 65%), increased activity of the sympathetic nervous system(LF/HF> 3.0), and high index of centralization (IC > 8).