Search PubMed⌕ Search

Biomedical subjects

F Marciano

Publications and source records attributed to F Marciano.

35 records · Page 2Linked to original sources
PubMed1994

Influence of reversible segmental left ventricular dysfunction on heart period variability in patients with one-vessel coronary artery disease.

OBJECTIVES: This study evaluated the relation between reversible segmental left ventricular dysfunction and frequency domain measures of heart period variability in patients with coronary artery disease. BACKGROUND: Heart period variability is frequently reduced in patients with coronary artery disease. However, the mechanisms of this reduction are still unclear. METHODS: Echocardiographic left ventricular wall motion and frequency domain measures of heart period variability were evaluated in 32 patients with one-vessel coronary artery disease before and 16 to 24 days after successful percutaneous transluminal coronary angioplasty. Of these, 12 patients (Group A) had normal and 20 patients (Group B) had abnormal regional wall motion. A control group of 15 healthy subjects (Group C) underwent 24-h Holter recording twice at 2-week intervals to check for spontaneous variations. RESULTS: At baseline, low and high frequency power were lower in Group B than in Groups A and C, whereas no difference was detectable in ultra low and very low frequency and total power. After coronary angioplasty, regional wall motion and frequency domain measures of heart period variability were unchanged in Group A. In Group B the mean (+/- SD) summed segment score improved from 17.1 +/- 3.6 to 12.8 +/- 2.0 (p < 0.01), and mean low and high frequency power (logarithmic units) increased from 6.14 +/- 0.23 to 6.35 +/- 0.34 (p < 0.01) and from 5.43 +/- 0.32 to 5.68 +/- 0.52 (p < 0.01), respectively. Furthermore, low and high frequency power, lower at baseline in Group B than in the other two groups, were comparable in the three groups after coronary angioplasty. CONCLUSIONS: This study demonstrates that segmental left ventricular dysfunction is involved in determining sympathovagal imbalance in patients with one-vessel coronary artery disease; the reversal of left ventricular dysfunction by successful coronary angioplasty improves the heart period power spectrum. Thus, alterations in cardiac geometry influence the discharge of afferent sympathetic mechanoreceptors, contributing to the derangement in autonomic control of heart rate.

Afferent Pathways↗
PubMed1994

Effects of converting enzyme inhibition on heart period variability in patients with acute myocardial infarction.

BACKGROUND: Heart period variability provides useful prognostic information on autonomic cardiac control, and a strong association has been demonstrated after myocardial infarction (MI) between cardiac mortality, sudden death, and reduced total power, ultralow-frequency (ULF) power, and very-low-frequency (VLF) power. Converting enzyme inhibitors are widely used in MI patients, but their influence on heart period variability remains to be defined. METHODS AND RESULTS: Time- and frequency-domain measures of heart period variability were calculated from 24-hour Holter monitoring in 40 patients with a first uncomplicated MI. After baseline examination between 48 and 72 hours after symptom onset, patients were randomly assigned to placebo or captopril administration, and on the third day, 24-hour Holter monitoring was repeated. No changes in time and frequency domain were detectable after placebo. After captopril, the SD of all normal RR (NN) intervals (SDNN) increased from 90 +/- 29 to 105 +/- 30 milliseconds (P < .01); the SD of the average NN intervals for all 5-minute segments (SDANN index) and the mean of the SDs of all NN intervals for all 5-minute segments (SDNN index) also increased from 74 +/- 24 to 90 +/- 26 milliseconds (P < .01) and from 45 +/- 17 to 49 +/- 15 milliseconds (P < .05), respectively. The root mean square successive difference (r-MSSD) and the percent of differences between adjacent NN intervals > 50 milliseconds (pNN50) remained unchanged. In regard to frequency-domain measures, after captopril, total power (ln unit) increased from 8.28 +/- 0.42 to 8.47 +/- 0.30 (P < .01); considering the frequency bands, a significant increase was observed in ULF (P < .01), VLF (P < .05), and low-frequency (LF) power (P < .05), whereas high-frequency (HF) power remained unchanged. CONCLUSIONS: This study supports the hypothesis that the renin-angiotensin system modulates the amplitude of ULF and VLF power. Furthermore, it demonstrates that in MI patients, converting enzyme inhibition favorably modifies measures of heart period variability strongly associated with a poor prognosis.

Aged↗
PubMed1994

[Effects of coronary angioplasty on heart rate variability explored in the domain of time and frequency in patients with one-vessel coronary disease].

BACKGROUND: Heart period variability is frequently reduced in patients with coronary artery disease. Although the mechanism for this reduction is still unclear, it seems to reflect alterations in cardiac autonomic control. In this study we have evaluated the relation between reversible segmental left ventricular dysfunction and time and frequency domain measures of heart period variability in patients with coronary artery disease. METHODS AND RESULTS: Echocardiographic segmental left ventricular wall motion and time and frequency domain measures of heart period variability were evaluated in 32 patients with one-vessel coronary artery disease before and 16-24 days after successful percutaneous transluminal coronary angioplasty (PTCA). At baseline examination 12 patients (Group A) had normal and 20 (Group B) abnormal regional wall motion. Prevalence of previous myocardial infarction was higher and mean angiographic ejection fraction lower in Group B than in Group A. At baseline, time domain measures were comparable between the 2 groups, while low frequency (LF) and high frequency (HF) power were lower in Group B than in Group A. After PTCA, in Group A regional wall motion and time and frequency domain measures of heart period variability were unchanged. In Group B summed segment score improved from 17.1 +/- 3.6 to 12.8 +/- 2.0 (p < 0.01) and a significant increase occurred in standard deviation of the average normal RR (NN) intervals for all 5-minute segments of a 24-hour recording (SDNN index), in root mean square successive difference (r-MSSD) and in the percentage of differences between adjacent NN intervals > 50 msec (pNN50). In this group also LF and HF power (logarithmic units) increased from 6.14 +/- 0.23 to 6.35 +/- 0.34 (p < 0.01) and from 5.43 +/- 0.32 to 5.68 +/- 0.52 (p < 0.01) respectively. There was no correlation between measures of heart period variability, summed segment score, and left ventricular ejection fraction. CONCLUSIONS: This study demonstrates that segmental left ventricular dysfunction is involved in determining sympathovagal imbalance in patients with one-vessel coronary artery disease; the reversal of left ventricular dysfunction by successful PTCA improves heart period variability. These findings support the hypothesis that alterations in cardiac geometry may influence the discharge of afferent sympathetic mechanoreceptors, thus contributing to the derangement in autonomic control of heart rate.

Aged↗
PubMed1987

Adrenal medulla grafts enhance recovery of striatal dopaminergic fibers.

The drug, 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP), depletes striatal dopamine levels in primates and certain rodents, including mice, and produces parkinsonian-like symptoms in humans and nonhuman primates. To investigate the consequences of grafting adrenal medullary tissue into the brain of a rodent model of Parkinson's disease, a piece of adult mouse adrenal medulla was grafted unilaterally into mouse striatum 1 week after MPTP treatment. This MPTP treatment resulted in the virtual disappearance of tyrosine hydroxylase-immunoreactive fibers and severely depleted striatal dopamine levels. At 2, 4, and 6 weeks after grafting, dense tyrosine hydroxylase-immunoreactive fibers were observed in the grafted striatum, while only sparse fibers were seen in the contralateral striatum. In all cases, tyrosine hydroxylase-immunoreactive fibers appeared to be from the host rather than from the grafts, which survived poorly. These observations suggest that, in mice, adrenal medullary grafts exert a neurotrophic action in the host brain to enhance recovery of dopaminergic neurons. This effect may be relevant to the symptomatic recovery in Parkinson's disease patients who have received adrenal medullary grafts.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1985

Relationship between CSF noradrenaline levels, C-EEG indicators of activation and psychosis ratings in drug-free schizophrenic patients.

A significant increase of cerebrospinal fluid (CSF) noradrenaline (NA) levels, probably reflecting a rise of central noradrenergic activity, has been observed in a sample of acute schizophrenic patients as compared with a population of subjects without personal or family history of major psychoses. CSF NA levels have been found to be significantly correlated with computerized EEG (C-EEG) indicators of arousal (negative correlation with alpha relative activity and positive correlation with alpha barycentric frequency and beta relative activity in frontal and central leads). No significant relationship has emerged between CSF NA concentration and psychosis ratings on CPRS as well as platelet MAO activity. These findings seems to confirm the link between central noradrenergic hyperactivity and the condition of enhanced arousal of the schizophrenic patient, although the role of this condition in the pathophysiology of schizophrenia (primary phenomenon or non-specific consequence of the stress related to the illness?) remains to be elucidated.

Adolescent↗
PubMed1980

Computerized EEG in schizophrenics.

20 psychiatric patients without pharmacologic therapy and an homogeneous control group of 19 healthy subjects have been submitted to an electroencephalographic (EEG) investigation. Computerized spectral analyses of the main EEG frequency bands have been performed. The spectra have been determined by some geometrical descriptors: the relative activity, the barycentric frequency and the barycentric radius; also classic descriptors have been used as complementary ones. In the EEG profile significant differences between patients and healthy subjects have been found. Some differences have also been observed among subgroups of schizophrenic patients. The geometrical descriptors applied in the EEG analysis are suggested as a useful method in the description of the basic characteristics of the main EEG frequency bands.

Adult↗
PubMed1979

Alpha increase in puerperium.

Significant increases of both alpha peak amplitude and power were found in the EEG after delivery as compared to those observed at the 32nd week of pregnancy. Controls failed to display the same gain in the alpha rhythm. The frequency was unaffected. Beside these quantitative changes no particular EEG pattern occurred. Neither the methodology nor habituation were considered responsible for these increases, which are also independent of the prolactin levels, because they were observable after blockage by bromocryptine, a drug which also fails to modify the EEG. Significant reduction of anxiety, tension and irritability was scored in the Hamiltonian test for depression. It is likely that both aspects depend on a common humoral process. The role of the progesterone drop is discussed.

Adult↗
PubMed1977

Applications of statistical equivalence to newborn EEG recordings.

Epochs were selected from sleep EEGs of newborns during both quiet and REM phases. A first order parameter analysis was done in order to test the homogeneity (run test and one way variance analysis) of the data within the epochs, follwed by a study of spectral equivalence between epochs. Comparisons were made between average spectra in the frequency range 0.5--4 c/sec; and between their band-by-band components, to test the feasibility of automatic classification of sleep stages by means of frequency analysis. On the basis of the statistical parameters we used, spectral analysis appears to be of limited value for the purpose of automatic classification of newborn EEG records; due to a lack of complete homogeneity of the spectra within each sleep state, it is not possible to identify a characteristic spectrum for active sleep and quiet sleep.

Electroencephalography↗