In our previous study, healthy volunteers showed considerable short-term dynamics and patterns of the coherence of high time resolution between respiratory movements (RESP), heart rate fluctuations (HRF), and arterial blood pressure fluctuations (BPF). These are physiological indicators of autonomic short-term coordination mediated mainly by the brainstem which could be impaired in severe brain disorders. We hypothesized a direct or indirect impairment of these functions by these disorders and examined these patterns in 16 patients suffering from severe brain disorders. We calculated partial and ordinary coherence sequences and found almost the same patterns of coherence sequences as in healthy volunteers, but a distinctly reduced frequency of pattern incidence in patients (2.8*1.5/10 min/patient and 9.5*2.8/10 min/subject, P<0.05). Furthermore, there is a significantly smaller frequency of HRF-related patterns in patients with poor outcome, compared with those in patients with good outcome (1.8*0.8/10 min/patient and 4.5*2.7/10 min/patient, P<0.05). We conclude that severe brain disorders reduce physiological short-term dynamics of autonomic coordination patterns in the mean values of patients, but not in every patient., U. Zwiener, Ch. Schelenz, S. Bramer, D. Hoyer., and Obsahuje bibliografii
The possible linear short-term coordination between respiratory movements (RESP), heart rate fluctuations (HRF), and arterial blood pressure fluctuations (BPF) in conscious human beings has not yet been investigated because of the restricted time resolution of conventional time series analysis. At present, this short-term dynamics as an expression of relative coordination can be quantified by newly developed adaptive autoregressive modeling of time series using Kalman filtering. Thus, in 6 conscious healthy volunteers, RESP, HRF, and BPF were recorded during 10 min in the supine position, at rest and during paced breathing. A considerable part of calculated ordinary and partial coherence sequences of short-term resolution between RESP and HRF, RESP and BPF, and partially between HRF and BPF showed patterns varying in time that could be correlated to changes between gradual coordinations (coherence changing between 0.40 and 0.95). They were more seldom complete or absent. There were mostly opposite changes between partial coherence sequences RESP-HRF/BPF and RESP-BPF/HRF demonstrating competitive behavior between these coordinations. Paced breathing did not essentially affect any observed characteristics. Therefore, these coherence dynamics are not essentially dependent on voluntary breathing movements. We conclude that to a different extent these linear and changing couplings between RESP, HRF, and BPF in conscious human beings exhibit properties of short-term complete and more frequently gradual coordinations showing dynamics that can not be determined by conventional methods., U. Zwiener, C. Schelenz, S. Bramer, D. Hoyer., and Obsahuje bibliografii