PubMed Health⌕ Search

Biomedical subjects

A Aissaoui

Publications and source records attributed to A Aissaoui.

5 recordsLinked to original sources
PubMed1994

Computing heart rate variability using spectral analysis techniques: HRVUAB, a ready-to-use program.

The application of spectral analysis techniques to study the nervous modulation of the vertebrate heart have given interesting results in clinical studies although nearly nothing is known in lower vertebrates. A program to compute this heart rate variability is described in detail and preliminary results are shown. Data is first statistically qualified and fragmented in smaller segments, each being further processed through linear trend removal and normalization before the application of the Fast Fourier Transform algorithm to estimate the interval spectrum. All consecutive periodograms are averaged and the interval spectrum plotted and saved.

Algorithms↗
PubMed1984

[Hodgkin's disease of the lung with cavitation and apparently primary. Apropos of a case].

The authors report a rare and diagnostically difficult clinical case of primary pulmonary Hodgkin's disease, with cavitation. They stress the diagnostic difficulties which they encountered: Indeed four stages are described in this case in which different diagnoses were considered as follows, a primary or secondary lung cancer, non-specific pulmonary suppuration, atypical hydated disease (as is frequently seen in Algeria) and finally pulmonary tuberculosis. The diagnosis of Hodgkin's disease was not considered until post-mortem. A review of the literature has called attention to the great rarity of cavitating Hodgkin's disease (only 53 cases in the world published). A clinical, radiological and anatomical study of the principal case published enhances the commentary on this rare case. In addition the pathogenesis of this granulomatous necrosis in Hodgkin's disease is discussed.

Hodgkin Disease↗
PubMedDate not supplied

Is the short-term modulation of heart rate in teleost fish physiologically significant? Assessment by spectral analysis techniques.

Heart rate is an important physiological variable in the control of cardiac output, even in fishes, where the importance of stroke volume has been overemphasized. Except for the myxinoids, the fish heart is innervated by cranial nerve X and the nature of this innervation is mainly inhibitory by parasympathetic fibers, although a sympathetic contribution has also been demonstrated. In mammals, cardiac innervation is not only responsible for the control of mean heart rate but it also modulates the beat-to-beat heart rate changes. These beat-to-beat changes are known as heart rate variability (HRV) and appear to be related to fluctuations in respiration and blood pressure. In this paper we demonstrate the link between cardiac innervation and HRV in several species of teleosts because HRV is greatly decreased after vagotomy or atropinization. In contrast, after abolishing the sympathetic influence with propranolol, only slight changes in total HRV are observed, indicating the restricted importance of the adrenergic innervation in determining phasic changes in HRV despite the significant tonic effect which has been demonstrated. Thus, it appears unlikely that the sympathetic influence will be present in any measured spectral component as suggested previously. Furthermore, clear spectral patterns do not always exist and this may be due to the erratic influence of respiration which is clearly faster than heart rate in all fish species studied. This differs from the slow ventilation frequency displayed by many mammalian species that exerts an influence on a beat-to-beat basis (respiratory sinus arrhythmia). Spectral patterns could also be affected by changing levels of circulating catecholamines, although this is still unproved.

Animals↗