Biomedical subjects
Publications and source records attributed to A Huch.
Magnetic resonance imaging (MRI) in the mediosagittal and transverse planes was used to measure the antero-posterior and transverse diameters of the minor pelvic cavity. The measurements for the diameters were larger than those usually found in the literature. The antero-posterior pelvic inlet diameter, the most important measurement for obstetrics, was on average 11.9 cm in contrast to the generally accepted length of 11.0 cm.
The aim of this study was to determine the minimum number of cardiac cycles necessary over which blood flow velocity representative of the situation (and not unduly influenced by sporadic irregularities). Blood flow was measured by Doppler ultrasound in the adult a. carotis communis, a. femoralis and fetal a. umbilicalis. The coefficients of variation (CV) for the Pulsatility Index (PI), Resistance Index (RI) and Time Average of Space Average Velocities (TASAV) from 10 averaged cycles were compared with the CVs of the respective indices from 2, 3, 4 up to 9 averaged cycles. The number of averaged cycles where the difference between the coefficients of variability became insignificant (Wilcoxon signed rank test) was taken to be the point at which representative values of PI, RI or, respectively, TASAV are assured. For PI evaluation for the a. carotis communis with either the 7 mx or 15 mx calculation program one needs to average over 7 cardiac cycles. Manually determining the maximum frequency curve envelope, 5 cycles are sufficient. Using these same calculation programs for the a. femoralis, 5, 6 and, respectively, 6, cycles are sufficient for representative PI indices; for the umbilical artery, 6, 8 and, respectively, 7 cycles are necessary. For RI, 5 cycles are sufficient in both the a. carotis communis and a. umbilicalis by manual evaluation. For TASAV, a minimum of 3 cycles for the a. carotis communis and of 7 for the a. femoralis are necessary. Thus the number of cardiac cycles which should be averaged is dependent on the vessel being examined, the index being calculated, and the program being used.
The aim of this study was the evaluation by Doppler sonography of blood flow velocity and waveforms in maternal (Femoral artery and vein, carotid artery, uteroplacental) and fetal (Umbilical artery) vessels before and after exercise. Thirteen healthy women with uncomplicated pregnancies (and outcomes) participated in the study between the 36th and 40th gestational week. Each proband underwent 5 exercise tests in a sitting position on a bicycle ergometer with a work load of 100 Watts during 3 minutes. The Doppler measurements were performed with Acuson 128. In the femoral and carotid arteries, peak velocities (systolic and end-diastolic, and for the femoral artery also post-systolic) as well as the mean blood flow velocities were measured. Mean blood flow velocity was also measured in the femoral vein. For the measurements of the arterial diameters, the M-Mode technique, for the femoral vein diameter, the B-Mode technique was used. The uteroplacental and umbilical blood flow waveforms were analysed by the Resistance and Pulsatility Indices. The maternal heart rate as well as systolic and diastolic blood pressures increased after each of the exercise tests. The mean blood flow velocity increased in both the femoral artery and vein while the vessel diameter remained constant. In the carotid artery, however, the velocity remained constant. An analysis of the velocity waveforms for the femoral artery showed in increase in the systolic and end-diastolic velocities as well as a reversal of the post-systolic flow, where the velocity is negative in a state of rest.(ABSTRACT TRUNCATED AT 250 WORDS)
The underlying pathogenesis of erythroblastosis fetalis is hemolysis of fetal red blood cells mediated by maternal antibodies. The resulting destruction of erythrocytes leads to progressive fetal anemia, and a hypervolemic condition develops in the fetus. The amount of maternal antibodies, real-time ultrasound, amniocentesis and/or cordocentesis can all be used to evaluate the degree of fetal anemia. The work presented here attempts to show that Doppler ultrasound can be used to detect the hypervolemic condition of anemic fetuses. One hundred fifty Doppler examinations were carried out on the aorta in 37 fetuses to evaluate the blood flow velocities and compare these with the fetal hematocrit. For the Doppler analysis, along with bidimensional echography, a Kranzbühler duplex scanner was used. In addition to the usual indices, the ratio of the median velocity to the maximum systolic velocity and an index of resistance using the maximum velocities 1/2 and 2/3 of the way through the cardiac cycle were calculated. Our examinations showed a significant increase in the temporal average of spatial average velocities (TASAV) and in the temporal average of maximum velocities (TAMV or M). The appearance of a spectral window was characteristic and a dicrotism in the curve was often observed. Much experience with the Doppler technique as well as a knowledge of factors influencing the blood flow velocity (caffeine, theine, nicotine, beta-sympathicomimetics) are necessary before attempting an interpretation of Doppler ultrasound results. Although the use of Doppler ultrasound does not yet permit a reduction in the number of invasive examinations, it does allow an improvement in the quality of surveillance of the fetal condition.
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Ebstein's anomaly is characterized by abnormalities both in the basal and in the free attachments of the leaflets of the tricuspid valve. Fairly frequently the developmental defect is associated with a WPW syndrome (Type B). The main obstetric problems arise from tachyarrhythmias. Since tachycardias in these patients are due to physical stress, correct planning of delivery calls for lightening of the hemodynamic burden of labor, careful analysis of the cardiac status, meticulous preparation for optimum antiarrhythmic therapy and correct timing for induction of labor. The case of a young primipara with Ebstein's anomaly is presented to typify the need for cooperation of subspecialities.
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Pulsed Doppler recordings of intracranial arterial velocity waveforms were made in 9 hydrocephalic fetuses during the second or third trimesters of pregnancy. Normal, increased, and decreased velocity waveform indices could be measured in these cases, and 1 fetus presented retrograde diastolic flow. Cerebral blood flow patterns of hydrocephalic fetuses seem to differ individually from case to case, presenting no uniform waveform type in late pregnancy. There was no obvious correlation between ventricular dilatation and the type of the velocity waveform.
608 high-risk pregnancies were monitored by repeated Doppler-examinations of the fetal aortic blood flow. An absent end-diastolic flow pattern was found to reveal fetal growth retardation with 73% sensitivity. The positive predictive value of this finding for prediction of fetal growth retardation combined with intrauterine distress (prevalence in the material 8%) was 85%. In the cases with this flow pattern, the cesarean section rate was 72%, and the mean gestational age at delivery was 34 weeks. Normal labor was not associated with any changes of umbilical arterial flow velocity waveforms, but the diastolic flow of the arcuate arteries was decreased during uterine contractions.
Against the background of dramatic changes that took place in the history of sports during the past one hundred years, we are today discussing with regard to the compatibility of sport and pregnancy whether the extent of sports activities before pregnancy contributes to the amount of stress tolerated during pregnancy. Animal experimental studies on the effect of physical stress on the foetus cannot always be transferred to man, and hence recommendations made to pregnant women are often purely empirical. The article reports on the results of an examination of a professional woman athlete during pregnancy: Various maternal circulatory and respiratory parameters were recorded in this primigravida of 25 years of age, who had been regularly active as a competitive runner for 12 years, during the 24th week of pregnancy and from the 28th week of pregnancy onwards, at intervals of 14 days and post partum, at rest and during steady-state load on a bicycle ergometer (6 minutes each at 40 and 70 watts load, respectively) and a step-by-step load increasing every minute by 15 watts until attainment of a maternal heart rate of 150 beats per minute. The results were compared with those in a group of pregnant women who had not been competitive sportswomen. During continued training as per schedule up to the 36th week of pregnancy of the athlete, there was hardly any change in performance, and there was a marked difference against the other women. The pulse at rest was lower by a mean of 30 beats in the athlete during pregnancy, clearly indicating maintenance of the economic cardiac mechanism known to occur in trained persons, which produces a greater cardiac output via an increased stroke volume at a lower heart rate. This difference was impressively demonstrated under different loads. Another example of more economic management of an identical load is also seen, for instance, in the lower oxygen uptake and lower respiratory rate. Even at a maternal heart rate of 150 beats per minute the foetus of the athlete did not show any signs of stress under test conditions. In a measurement "at site" during the 38th week of pregnancy under routine and training conditions with relevant sprints and a maternal heart rate increase to more than 170 beats per minute, however, foetal behaviour displaying bradycardia clearly showed the existence of tolerance limits for foetal supply.(ABSTRACT TRUNCATED AT 400 WORDS)
Between the 20th and 40th week of pregnancy in 40 normal single-fetus pregnancies, examinations were carried out at regular intervals to determine prospectively the influence of gestation age and maternal posture on fetal heart rate patterns. It could be demonstrated that both fetal maturation as pregnancy progresses and differing maternal postures lead to significant changes in the fetal parameters. Failure to take these influences into consideration can lead to a false assessment of the condition of the fetus.
Blood flow velocity waveforms in large maternal and uterine vessels were measured longitudinally from 16 weeks gestation onwards until 12 weeks postpartum in 21 singleton pregnancies by duplex sonography. In the maternal carotid artery, time average mean velocity (TAVmean) did not show significant changes. In both the femoral artery and vein, however, significant changes were observed. In the femoral artery, TAVmean and systolic maximum velocities decreased with advancing gestation. In the femoral vein, TAVmean remained constant throughout pregnancy and was lower than postpartum. The resistance index in the uterine arteries decreased with advancing gestation and increased after delivery. Among many factors contributing to femoral arterial blood flow velocity changes in pregnancy, we suggest that a major one is the increase in uterine blood flow. Reduction in venous femoral blood flow velocity and increase in the femoral vein diameter might be associated with the common occurrence of venous disorders in pregnancy.
We present the prenatal ultrasonographic findings of an echo-dense solid mass above the normal left kidney and below the diaphragm. This mass was diagnosed as extralobar lung sequestration (ELS) at laparotomy of the child. ELS (or accessory lungs) is a rare congenital abnormality defined as a lung segment outside a normal lung, usually localized in the left lower thorax. A subdiaphragmatic localization is rare. The prognosis depends upon both the presence (as found in over 50% of reported cases) and severity of additional congenital anomalies.
Normal levels of unconjugated estriol and human placental lactogen hormone in the maternal serum and a normal, reactive pattern of non-stress test cardiotocography were recorded in a case of advanced abdominal pregnancy with surviving newborn. The placenta was inserted at the base and side walls of fossa Douglas. Fetal, umbilical and retroplacental arterial Doppler ultrasound examinations revealed normal velocity waveforms. These findings indicated that the trophoblast invasion to the retroplacental arteries also occurs when the placenta has an extra-uterine insertion, and this can result in a normal placental blood supply and function.
In bipolar electrocoagulation of the fallopian tubes, the electric current is between the tips of the forceps, which are visualized. Therefore, unnoticed burn injuries are uncommon. We describe a case of ureteral stenosis due to inadvertent burn injury, which was successfully managed conservatively.
Uterine arterial velocity waveforms, recorded by pulsed Doppler technology, demonstrated a significant increase in vascular resistance after the first postpartum day until the fourth to sixth postpartum week. In patients with an isthmic postcesarean hemorrhage, partial placental retention and puerperal endometritis, the corresponding waveforms presented higher diastolic velocity components than was the case for normal puerperal courses, indicating that lower uterine vascular resistance might be associated with these complications.
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Spectrophotometric methods with CO-oxymeters for measurements of carboxyhemoglobin and/or oxygen saturation in human blood include a systematic error depending on the percentage of fetal hemoglobin. It is of clinical importance to estimate the fetal hemoglobin to correct HbCO and SO2 values respectively. The described method is simple and less time consuming than conventional methods like HPLC or electrophoresis. The two measurements of oxy- and carboxyhemoglobin in the same blood sample with different oxygen saturation are needed for the estimation of the HbF and can be performed, including the deoxygenation procedure, in about 40 minutes.