Showing papers by "Chiara Cogliati published in 2001"

Sympathetic rhythms and cardiovascular oscillations.

Abstract: Spectral analysis of heart rate and arterial pressure variabilities is a powerful noninvasive tool, which is increasingly used to infer alterations of cardiovascular autonomic regulation in a variety of physiological and pathophysiological conditions, such as hypertension, myocardial infarction and congestive heart failure. A most important methodological issue to properly interpret the results obtained by the spectral analysis of cardiovascular variability signals is represented by the attribution of neurophysiological correlates to these spectral components. In this regard, recent applications of spectral techniques to the evaluation of the oscillatory properties of sympathetic efferent activity in animals, as well as in humans, offer a new approach to a better understanding of the relationship between cardiovascular oscillations and autonomic regulation.

Spectral analysis of muscle sympathetic nerve activity in man

Abstract: Recent applications of frequency domain analysis to the variability of muscle sympathetic nerve activity (MSNA) have improved the comprehension of the relationship between cardiovascular oscillations and the autonomic nervous system. It has been observed that spectral analysis of MSNA is characterized by two major oscillatory components at low (LF) and high (HF) frequencies, similar to those detectable in the variability of cardiovascular signals. Pharmacological and non-pharmacological studies have shown that, at least within the physiological range, the two MSNA rhythms show a reciprocal behavior, similar to that already observed for cardiovascular oscillations. The oscillatory pattern of MSNA provides non-redundant but complementary information with respect to the time domain measures of MSNA (burst rate and amplitude) since it has been shown that completely different spectral profiles may be derived from various MSNA recordings. On the other hand, the latter are instead comparable in terms of mass activity. Due to the intrinsic characteristics of the signal, which represents the direct outflow of the central neural structures of the cardiovascular autonomic nervous system, this approach can be considered as a unique window over the central organization of excitatory and inhibitory neural mechanisms responsible for the genesis and the regulation of cardiovascular oscillations.