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Biomedical subjects

D Arduini

Publications and source records attributed to D Arduini.

At least 109 records · Page 6Linked to original sources
PubMed1990

Doppler echocardiographic assessment of time to peak velocity in the aorta and pulmonary artery of small for gestational age fetuses.

The time to peak velocity was measured at the level of the ascending aorta and pulmonary artery by Doppler echocardiography in 38 small-for-gestational age (SGA) fetuses before and during maternal hyperoxygenation. The values were compared to a reference range derived from the study of 142 appropriate-for-gestational age (AGA) fetuses. In the SGA fetuses the time to peak velocity at the level of pulmonary artery was significantly lower and at the level of the aorta significantly higher than in AGA fetuses. During maternal hyperoxygenation the aortic time to peak velocity decreased towards normal range but there was no significant change at the level of the pulmonary artery. These results may indicate variations of aortic and pulmonary pressures in SGA fetuses that can be partially modified by maternal hyperoxygenation and which may be associated with changes in the peripheral resistance of the cerebral circulation.

Aorta, Thoracic↗
PubMed1990

Effects of maternal hyperoxygenation on atrioventricular velocity waveforms in healthy and growth-retarded fetuses.

In order to assess whether maternal hyperoxygenation induces modifications of Doppler-measured velocity waveforms across atrioventricular valves, 15 healthy and 15 growth-retarded fetuses were studied in basal conditions and during the maternal administration of 60% humidified oxygen. Recordings were performed at 5-min intervals before, during and after maternal oxygen administration. In basal conditions, growth-retarded fetuses exhibited significantly lower ratios between the velocities during early passive ventricular filling and active ventricular filling (E/A ratio) at the level of both mitral and tricuspid valves when compared to healthy fetuses. Furthermore in healthy fetuses the velocity time integral across the tricuspid valve always slightly exceeded that across the mitral valve, whilst growth-retarded fetuses showed an inversed ratio between these velocities. During oxygen administration no changes were found between the two groups of fetuses with regard to the E/A ratios. Similarly the velocity time integrals were unaffected by oxygen administration in the healthy fetuses. Besides growth-retarded fetuses exhibited significant temporary modifications during oxygen administration as expressed by an increase in the velocity time integral across the mitral valve associated with a decrease of that across the tricuspid. These changes result in an inversion of the ratio between transtricuspid and transmitral velocity time integrals reaching values similar to those of healthy fetuses. Short-term oxygen administration affects the intracardiac flow redistribution present in growth-retarded fetuses bringing it to a pattern similar to that of healthy fetuses whereas the E/A ratios were not affected by the treatment.

Blood Circulation↗
PubMed1990

Normal values of Pulsatility Index from fetal vessels: a cross-sectional study on 1556 healthy fetuses.

In a cross-sectional study of 1556 uncomplicated pregnancies velocity waveforms were recorded at the level of fetal umbilical artery, descending aorta, renal artery, internal carotid artery and middle cerebral artery. Reference limits for the Pulsatility Index of each vessel were constructed by regression analysis and a progressive fall during gestation was evidenced in all the vascular districts investigated with the exception of descending aorta. Furthermore we calculated the ratios between Pulsatility Index values of cerebral and peripheral vessels which may be relevant for the early diagnosis of the haemodynamic abnormalities occurring during the brain sparing effect.

Arteries↗
PubMed1990

Functional assessment of uteroplacental and fetal circulations by means of color Doppler ultrasonography.

A study was made in order to assess whether the combined use of color flow mapping and conventional pulsed Doppler could improve the accuracy of blood flow velocity waveform analysis in fetal and placental circulations. Fifty patients were studied at 18 to 20 or 26 to 28 weeks of gestation by two trained investigators by means of either conventional Doppler or conventional Doppler plus color flow mapping. Recordings were performed at the level of the uterine arteries, umbilical artery, descending aorta, and internal carotid artery. The experimental procedure was repeated the following day with the patients undergoing the alternate technique of recording. In all the vascular districts investigated, color flow mapping allowed us to obtain a higher number of reliable recordings, to shorten the observation time, and to reduce the intra- and interobserver coefficient of variations.

Aorta, Thoracic↗
PubMed1989

Behavioural state transitions in healthy and growth retarded fetuses.

The transitions, i.e. time intervals between two different behavioural states, were studied in 10 healthy and 10 growth retarded fetuses (IUGR) in near term pregnancies. In healthy fetuses, transitions usually lasted less than 3 min whereas IUGR fetuses showed a longer duration when compared to healthy fetuses. Moreover, a significant trend in the change of state variables (fetal heart rate, fetal eye movements and fetal gross body movements) was evident in healthy fetuses: fetal heart rate was the first variable to change in transitions from 1F to 2F and the last variable to change in transitions from 2F to 1F. On the other hand IUGR fetuses showed a random sequence in order of change. These findings were substantiated by the intraindividual consistency evidenced in repeated recordings. In conclusion the analysis of transitions differentiates between healthy fetuses and those affected by IUGR.

Blood Flow Velocity↗
PubMed1989

Tryptophan availability and fetal behavioral states.

Behavioral state instability in growth-retarded fetuses might be related to a decrease in serotonine production. Tryptophan maternal and cord blood values after elective cesarean section have been investigated by means of high performance liquid chromatography in 20 growth-retarded fetuses due to pregnancy-induced hypertension (PIH) and 20 normal pregnancies as control group. The feto-maternal ratio of tryptophan is significantly higher in normal fetuses than in PIH growth-retarded fetuses (p less than 0.001). Behavioral states have been determined 1 week and just before cesarean section. Values of 1F, 2F, 3F and 4F differ in the 2 groups (p less than 0.001). A higher percentage of non-coincidences (p less than 0.001) and state interruptions (p less than 0.001) is found in PIH fetuses. A significant correlation is demonstrated between the increase of non-coincidences and decrease in the feto-maternal Trp ratio (p less than 0.001).

Female↗
PubMed1989

Are blood flow velocity waveforms related to umbilical cord acid-base status in the human fetus?

Doppler blood flow velocity waveforms from fetal umbilical artery, descending aorta, internal carotid artery and maternal uterine arteries were recorded in 50 fetuses near term undergoing cesarean section before the onset of labor in order to evidence eventual relationships with the fetal acid-base status. The primary indications for cesarean section were in 16 cases an elective repeated cesarean section and in the remaining cases maternal hypertension often associated with fetal growth retardation and/or fetal distress. The technique of anesthesia was strictly standardized and fetal blood gas levels and acid-base status were analyzed in umbilical artery and vein immediately after birth. A significant correlation was found between the pulsatility index from internal carotid artery and the pO2 levels in umbilical vein (r = 0.87; p less than or equal to 0.001). Similar relationships were found between the pulsatility index from descending aorta and the pCO2 (r = 0.78; p less than or equal to 0.001), base excess (r = 0.72; p less than or equal to 0.001) and pH (r = 0.80; p less than or equal to 0.001) levels in umbilical artery. It is suggested that Doppler ultrasound could be useful in the diagnosis of fetal hypoxia and acidosis.

Acid-Base Equilibrium↗
PubMed1989

Hemodynamic changes in growth retarded fetuses during maternal oxygen administration as predictors of fetal outcome.

The changes in fetal hemodynamics during maternal administration of 60% humidified oxygen were assessed by Doppler ultrasonography in 15 growth retarded fetuses characterized by abnormal blood flow velocity waveforms. During oxygen treatment, nine fetuses exhibited temporary hemodynamic modifications as expressed by a recovery toward the normal range of vascular impedance in the descending aorta and internal carotid artery, whereas no changes were found in the remaining six fetuses. In this latter group, a rapid deterioration of fetal condition occurred and all the fetuses were delivered by emergency cesarean section within 9 days from the Doppler examination. The absence of recovery of vascular resistance during acute maternal oxygen administration seems therefore to be a useful marker of imminent acute distress in fetuses with growth retardation secondary to chronic hypoxia.

Blood Flow Velocity↗
PubMed1989

Prenatal cerebral Doppler ultrasonography and neonatal neurologic outcome.

The significance of fetal cerebral blood flow analysis in the prediction of neonatal neurologic outcome was investigated on 87 fetuses at risk for chronic hypoxia. Blood flow velocity waveforms were recorded from the fetal internal carotid artery immediately before cesarean section; newborns underwent neurologic follow-up until discharged from the neonatal division. Neonatal outcome was considered abnormal in presence of a postasphyxial encephalopathy. Receiver operating characteristic curves were used to demonstrate the efficacy of fetal cerebral blood flow velocity waveform analysis as a predictor of neonatal outcome. A value of the pulsatility index from the internal carotid artery below the second standard deviation of our range of normality was found to be a powerful indicator of the development of neonatal neurologic abnormalities (Cohen's Kappa index = .58). These results were particularly evident in fetuses with a birthweight above 2500 g in which a specificity of 93.7%, a sensitivity of 75%, and an accuracy of 89.7% were achieved.

Central Nervous System Diseases↗
PubMed1988

Computer-assisted analysis of fetal behavioural states.

A computerized system which simultaneously acquires and quantifies several ultrasonically detected fetal activities, including gross body movements, breathing movements, and eye movements, was developed in order to obtain additional quantitative data on fetal behaviour. Movements were automatically related to fetal heart rate allowing computation of their mean incidence, duration, lag time and percentage time spent moving during different heart rate patterns. The incidence of various behavioural states was also calculated. The study of 15 healthy fetuses near term revealed the existence of statistically significant differences in these parameters between low and high variability patterns of fetal heart rate suggesting a quantitative modulation of fetal movements by behavioural states.

Computer Graphics↗
PubMed1988

Short-term effects of maternal oxygen administration on blood flow velocity waveforms in healthy and growth-retarded fetuses.

To determine whether maternal oxygen administration affects fetal hemodynamics, we investigated 10 healthy fetuses and 10 growth-retarded fetuses near term by means of Doppler ultrasonography. The growth-retarded fetuses were characterized by abnormal blood flow velocity waveforms. Velocity waveforms were simultaneously recorded at 5-minute intervals from the fetal descending aorta and internal carotid artery before, during, and after maternal oxygen administered through a face mask that delivered 60% oxygen. The pulsatility index was calculated. During oxygen treatment growth-retarded fetuses showed significant temporary hemodynamic modifications as expressed by changes of pulsatility index values that increased in the internal carotid artery and decreased at the level of the descending aorta. On the other side no changes were found in healthy fetuses. These findings suggest that maternal oxygen administration can modify fetal hemodynamics in cases of growth retardation associated with abnormal blood flow velocity waveforms.

Analysis of Variance↗
PubMed1988

Doppler echocardiographic assessment of atrioventricular velocity waveforms in normal and small-for-gestational-age fetuses.

A prospective longitudinal study determined the physiological patterns of blood flow velocity waveforms in normal and in small-for-gestational-age (SGA) fetuses. Using a Pulsed Doppler Duplex system, 125 normally grown fetuses and 35 SGA fetuses were studied longitudinally at between 27 and 42 weeks gestation. In normal fetuses the ratio between the E velocity (early passive ventricular filling) and the A velocity (active ventricular filling during atrial contraction) increased progressively during pregnancy in both transmitral and transtricuspid waveforms, approaching 1 at term. In SGA fetuses, the E/A ratios did not increase during pregnancy and the values obtained were significantly lower than in normal fetuses. The ratio between the transtricuspid and transmitral mean temporal velocities remained almost constant throughout pregnancy in the normal fetuses with transtricuspid velocity slightly exceeding the transmitral velocity. On the other hand, in SGA fetuses the ratio between the mean temporal velocities was inversed with the transmitral velocity progressively greater than the transtricuspid velocity suggesting the existence of intracardiac haemodynamic changes in these fetuses.

Blood Flow Velocity↗
PubMed1988

Differential diagnosis of small-for-gestational age fetuses by Doppler ultrasound.

The purpose of this investigation was to compare the efficacy of conventional ultrasonographic measurements (i.e. head to abdomen circumference ratio, amount of amniotic fluid) with Doppler ultrasonography in the differential diagnosis of small-for-gestational age (SGA) fetuses. Blood flow velocity waveforms were recorded from the umbilical artery descending aorta and internal carotid artery in 121 intrauterine growth-retarded fetuses and the pulsatility index was evaluated as an index of vascular impedance. Conventional ultrasonographic measurements were of limited usefulness in the differential diagnosis, whereas the ratio between the pulsatility indexes from umbilical and carotid arteries proved to be a good index for discriminating SGA fetuses due to low growth potential (congenital infections, structural anomalies, chromosomal abnormalities, constitutional factors) from those caused by placental dysfunction (specificity 96.6%, sensitivity 89%, positive predictive value 98.7%, negative predictive value 74.3% and accuracy 90.9%.

Amniotic Fluid↗
PubMed1988

Computerized analysis of behavioural states in asymmetrical growth retarded fetuses.

The fetal behaviour of 15 asymmetrical intrauterine growth retarded (IUGR) fetuses was compared to that of a control group of healthy fetuses. Fetuses underwent simultaneous cardiotocographic and ultrasonographic examinations for 2 consecutive hours at 36-38 weeks' gestation. Behavioural states analysis was carried out by means of a computerized system (Digital PDP 11) that allowed the recording of several fetal variables including heart rate (FHR), gross body movements (FM), eye movements (FEM) and breathing movements (FBM). FHR was classified in four different patterns (FHRP) according to Nijhuis et al.; fetal movements were automatically synchronized with FHR and grouped for each FHRP. Several quantitative parameters (i.e. incidence, mean duration, lag time, % time spent moving) were then computed for each movement. There were no statistical differences in the distribution of FHRP between healthy and IUGR fetuses. On the other hand quantitative differences were found when the movements investigated were related to FHRP. In IUGR fetuses FEM were mainly represented by low frequency movements (IEM) during both low (FHRP A) and high variability (FHRP B) FHRP, whereas healthy fetuses exhibited mostly rapid eye movements (REM) during FHRP B and absent type of FEM during FHRP A. Moreover IUGR fetuses showed a reduction of state 1F (quiet sleep) and an increase of periods of no coincidence between behavioural state variable when compared to the control group fetuses. These findings, therefore suggest the existence of quantitative differences in fetal behaviour in asymmetrical IUGR fetuses when compared to healthy fetuses.

Cardiotocography↗