PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “FETAL HEART”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
PubMed1988

Fetal heart rate changes after fetal intravascular treatment with pancuronium bromide.

Because of recurrent needle dislodgement secondary to fetal movement, we have altered our intravascular transfusion technique by replacing maternal premedication (meperidine and diazepam [group 1]) with fetal intravascular infusion of pancuronium bromide (Pavulon [group 2]), a nondepolarizing neuromuscular blocking agent. Baseline fetal heart rate, number of accelerations, and variability were assessed before and after transfusion in both groups. Whereas there were no changes after transfusion in the former group, those fetuses who received pancuronium bromide demonstrated a dramatic abolishment of accelerations and decrease in variability, with the heart rate pattern often appearing "sinusoidal-like." These alterations in fetal heart rate were temporary changes that reverted to normal once the fetus "awakened" from the neuromuscular blockade. We speculate that these changes in fetal heart rate are secondary to the interaction of the reported hypertensive and vagolytic effects of pancuronium bromide.

Blood Transfusion, Intrauterine↗
PubMed1980

Intrapartum fetal heart rate monitoring. IV. Observations on elective and nonelective fetal heart rate monitoring.

Heart rate tracings and outcome in 919 electively and 1,077 nonelectively monitored fetuses were compared in order to investigate the value of elective surveillance of the fetal heart rate (FHR) in either group. A threefold higher perinatal mortality and a twofold higher number of low 5-minute Apgar scores were observed among patients with risk factors compared to electively monitored pregnancies. In the beginning of monitored labor, fetuses with risk factors exhibited a higher incidence of FHR patterns with low FHR variability than fetuses without risk factors. In the final phase of labor, FHR patterns indicative of hypoxia, i.e., late decelerations and severe and atypical variable decelerations, were found more often in the nonelective than in the elective group. Umbilical cord problems reflected by the occurrence of variable deceleration were responsible for the majority of low Apgar scores observed among electively monitored fetuses. The findings and their implications for FHR monitoring are discussed.

Female↗
PubMed2000

A comparison of visual analyses of intrapartum fetal heart rate tracings according to the new national institute of child health and human development guidelines with computer analyses by an automated fetal heart rate monitoring system.

OBJECTIVES: The aim of this study was to compare the visual analyses of fetal heart rate tracings by observers according to recent National Institute of Child Health and Human Development interpretative guidelines both with each other and with those of a computerized fetal heart rate analysis and alerting system. STUDY DESIGN: One-hour sections of intrapartum fetal heart rate records were analyzed by a computerized monitoring system (Hewlett-Packard TraceVue; HP GmbH, Böblingen, Germany) and by 4 observers (a registered obstetric nurse, a certified nurse-midwife, an obstetrics resident physician, and a physician maternal-fetal medicine faculty member) instructed to use the new National Institute of Child Health and Human Development guidelines. We compared specific alerts, baseline rates, frequencies of accelerations and decelerations, and signal quality assessments generated by the TraceVue system and the observers. Power analysis indicated that 50 tracings were required to detect interobserver and observer-computer agreement levels of 80% +/- 10%. Statistical comparisons used kappa coefficient, chi(2) test, and analysis of variance with repeated measures as appropriate. RESULTS: Levels of agreement between observer pairs and the computer did not vary significantly across successive 10-minute intervals. Overall levels of interobserver agreement for baseline rate, tracing quality assessment, frequencies of accelerations and decelerations, and alerts ranged from 45% to 99% and were highest for baseline rate and signal loss and lowest for acceleration and deceleration counts. Interobserver agreement for alerts was relatively high (range, 72%-84%), with virtually no difference between any of the observers and the computer (range, 76.9%-79.2%; kappa = 0.25). CONCLUSION: Use of the National Institute of Child Health and Human Development guidelines for visual fetal heart rate interpretation did not increase agreements on most fetal heart rate features beyond those expected by chance or noted in previous reports. These guidelines did appear to blunt some interpretive differences, possibly as a result of observer background. Although levels of agreement on fetal heart rate features differed, agreements on clinical alerts were similar among all observers and a computerized fetal heart rate monitoring system. Computer analysis of fetal heart rate tracings could eliminate interobserver variation that results from visual analysis and could produce more consistent clinical responses to normal and abnormal fetal heart rate patterns.

Automation↗
PubMed1998

Correlation of fetal oxygen saturation to fetal heart rate patterns. Evaluation of fetal pulse oximetry with two different oxisensors.

BACKGROUND: The purpose of this study was the correlation of fetal oxygen saturation values to various fetal heart rate patterns, as well as to oxygen saturation values obtained by fetal blood analysis. These objectives need to be evaluated from the perspective that two generations of fetal oxisensors have been used. METHODS: Two different oxisensor systems (FS10: 660+890 nm and FS14: 735+890 nm) and a blinded pulse oximeter (type N400, Nellcor Puritan Bennett) were utilized to monitor 112 fetuses. All data, including oxygen saturation, fetal heart rate patterns, signal and contact quality were stored on a personal computer and evaluated after delivery. RESULTS: The following median fetal oxygen saturation values were obtained: during reassuring fetal heart rate sequences 54% with the oxisensor FS10 and 48% with the newer FS14 oxisensor, during intervals of variable decelerations 43% with the FS10 oxisensor and 40% with the FS14 oxisensor. These differences between values obtained during normal and abnormal fetal heart rate patterns are significant. Due to non-reassuring fetal heart rate patterns 81 fetal blood analyses were performed. The values of pulse oximetry were 9% higher (6% for the FS14) than those of spectrophotometry. Correlation of both methods was r=0.66 (0.74 for the FS14). CONCLUSIONS: In combination with fetal heart rate monitoring, fetal pulse oximetry promises a better differentiation between low and high risk heart rate patterns. Oxygen saturation values from intermittent fetal blood sampling reassure the clinician concerning the accuracy of this new method of intrapartum fetal surveillance and underline the increased quality of the new generation of oxisensor using light of a wavelength of 735 and 890 nm.

Cohort Studies↗
PubMed1998

Fetal heart rate patterns in postasphyxiated fetal lambs with brain damage.

OBJECTIVE: We previously showed that in asphyxiated fetal lambs the duration of hypotension correlated well with the severity of histologic damage to the brain, whereas the duration of bradycardia did not. This study compares fetal heart rate patterns with the degree of histologic damage to the brain. STUDY DESIGN: Twelve chronically instrumented near-term fetal lambs were subjected to asphyxia by umbilical cord occlusion until fetal arterial pH was <6. 9 and base excess was <-20 mEq/L. An additional 4 fetuses served as sham-asphyxia controls. Fetal heart rate (from electrocardiogram), arterial blood pressure, fetal breathing movements, and electrocorticogram were continuously monitored before, during, and for 72 hours after asphyxia. Fetal brain histologic features were categorized as mild (group 1, n = 5), moderate (group 2, n = 4), and severe (group 3, n = 3). Long-term fetal heart rate variability expressed as amplitude range was assessed visually every 5 minutes from 30 minutes before asphyxia until 2 hours of recovery and at 6, 12, 24, 48, and 72 hours of recovery. RESULTS: Long-term fetal heart rate variability amplitude decreased from 32 +/- 17 beats/min (mean +/- SEM) preocclusion to 4 +/- 13 beats/min at the end of occlusion (P <.001) without significant differences among the 3 groups. During 10 to 45 minutes of recovery, the long-term variability of group 1 was significantly greater than that of groups 2 and 3. At 24 to 72 hours of recovery, the long-term variability of groups 1 and 2 was significantly higher than that of group 3, which was almost 0. The "checkmark" and sinusoidal fetal heart rate patterns were observed during the recovery period in groups 2 and 3. CONCLUSIONS: Decreased long-term fetal heart rate variability and the "checkmark" and sinusoidal fetal heart rate patterns were indicators of the severity of asphyxial histologic damage in the fetal brain.

Animals↗
PubMed1980

Changes in the fetal heart rate associated with fetal breathing and fetal movement.

Thirty-eight recordings of fetal heart rate and fetal activity were made from 21 normal patients between 36 and 41 weeks gestation. Each recording lasted for an average of 39 minutes. The heart rate was measured from beat to beat using the R-wave of the fetal electrocardiogram as the indicator of each heart-beat. Fetal breathing movements and fetal body movements were detected using either A-mode or B-mode ultrasound systems. The relation of fetal breathing and fetal movement to the fetal heart rate was studied both by cardiotachography and computer analysis of the R--R intervals. Fetal body movements (kicking and rolling) were usually associated with a brief tachycardia, the latter typically occurring every two to three minutes. In 14 recordings, the periods of fetal activity were interrupted by periods of fetal rest with an average duration of 12.5 minutes. Fetal breathing was seen in 26 of the 34 recordings analysed and occurred principally during the periods of fetal activity. Fetal breathing was associated with a significant increase in heart rate variation measured as the standard deviation of the R--R intervals and the mean absolute R--R interval difference. Sometimes a pattern of respiratory sinus arrhythmia was seen.

Electrocardiography↗
PubMedDate not supplied

Modifications of ultradian and circadian rhythms of fetal heart rate after fetal-maternal adrenal gland suppression: a double blind study.

In order to verify whether fetal and maternal adrenal gland suppression induces effects on fetal behaviour, triamcinolone was administered to five healthy pregnant women at 35 weeks of gestation. Five patients of the same gestational age were used as control. Fetal heart rate (FHR) and fetal movements were recorded continuously over 2-h interval by means of cardiotocography. After 3 weeks (38 weeks of gestation) the recordings were repeated without drug administration. Cortisol, adrenocorticotropin hormone, 17 beta-estradiol and unconjugated estriol were measured at the same time every 2 h in maternal peripheral plasma. At 35 weeks we found a loss of circadian rhythms of the hormones investigated and modifications of ultradian and circadian patterns of FHR in the treated group with respect to the control. No differences in hormonal and biophysical parameters were found between the two groups after the end of treatment (38 weeks). These data suggest that the inhibition of fetal and maternal adrenal glands could cause modifications of FHR patterns.

Activity Cycles↗
PubMed1996

Maternal infusion of antioxidants (Trolox and ascorbic acid) protects the fetal heart in rabbit fetal hypoxia.

The antioxidants, Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid, a water soluble analog of vitamin E) and ascorbic acid (AA), protect the heart from ischemia-reperfusion injury. We hypothesized that maternal infusion of Trolox and AA, would reduce the fetal bradycardia and myocardial damage observed in fetal hypoxia and increase the total antioxidant activity in fetal plasma. Either i.v. saline (control group) or Trolox + AA (drug group) was randomly administered to 29-d-old pregnant rabbits. Fetal hypoxia was induced by uterine ischemia. Fetal heart rate, plasma CK-MB activity, and plasma total radical antioxidant potential (TRAP) were measured in different sets of animals. Fetal heart rate in the drug group was higher than in the control group for the first 35 min (p < 0.05 at every 5-min interval). Fetal bradycardia (<60 beats/min) occurred after 39 min (median) in the drug group, and 29 min in the control group (p < 0.05). After 50 min of hypoxia, plasma CK-MB was lower in the drug group, 1204 +/- 132 U/L (mean +/- SEM), than in the control group, 2633 +/- 233 U/L (p < 0.05). TRAP was higher in the drug group, 3.01 +/- 0.15 mM (Trolox equivalent concentration), than in the control group, 1.48 +/- 0.27 mM (p < 0.05). Higher TRAP levels (> or = 2.0 mM) were associated with lower CK-MB levels (<2500 U/L) (p < 0.05). Administration of Trolox and AA to the mother has a beneficial effect on fetal myocardial damage after fetal hypoxia, and a small beneficial effect on fetal bradycardia during hypoxia. The beneficial effect may be due to the augmentation of fetal plasma antioxidants from maternal antioxidant pretreatment.

Animals↗
PubMed1982

The association between fetal heart rate patterns and fetal movements in pregnancies between 20 and 30 weeks' gestation.

The relationships between fetal heart rate (FHR) patterns and fetal movements (FM) were evaluated in 20 normal fetuses between 20 and 20 weeks' gestation. In 10 fetuses at 20 to 22 weeks' gestational age, 602 of the 620 observed FHR changes (97.1%) were decelerations. In this same group, most of the FHR changes (62.4%) were associated with FM. Similarly, 387 of 569 (68%) recorded FM between 20 and 22 weeks' gestation were associated with FHR changes. In a second group of fetuses between 28 and 30 weeks' gestation, in contrast to the less mature group, 227 of 670 FHR changes (33.9%) were decelerations. Among the remainder of the FHR changes, 240 (35.8%) were accelerations and 203 (30.3%) were accelerations with decelerations. As in the less mature group of fetuses, most of the FHR changes in these older fetuses were associated with FM (81.8%) and 548 of 611 (89.7%) recorded FM were associated with FHR changes. In summary, in normal pregnancy, FHR decelerations are common between 20 and 30 weeks' gestation. With advancing gestation, FHR decelerations are less commonly seen, and the frequency of acceleration and acceleration/deceleration patterns increases. The association between FHR and FM becomes stronger with advancing gestational age between 20 and 30 weeks. These findings suggest that the criteria for evaluating the health of the fetus before 30 weeks may be different from the criteria used later in pregnancy. Consequently, in the evaluation of low-birth weight fetuses between 20 and 30 weeks' gestation, new criteria for normal and abnormal nonstress monitoring tests must be developed.

Electrocardiography↗
PubMed1981

Antepartum fetal heart rate monitoring. A semi-quantitative evaluation of the 'non-stressed' fetal heart rate.

1964 recordings (from 246 patients were analysed on the basis of a semi-quantitative evaluation of base-line heart rate variability. All the tracings were obtained in the antepartum period, between the 20th wk of pregnancy and prior to the onset of labour. None of the recordings were made during labour or after induction of uterine activity so that a 'non-stressed' fetal heart rate test was obtained in every case. The percentage of flat tracing in each recording and the presence of sinusoidal patterns were compared with the neonatal outcome. When the tracings included a more than 50% flat pattern, 81.8% of the babies were distressed at birth. When a less than 50% flat recording was present only 11.4% of the neonates were distressed. Sinusoidal patterns were more frequently associated with abnormal tracings including those with more than 50% flat recordings. The presence of sinusoidal features did not significantly influence the neonatal outcome for tracings with a less than 50% anomaly: conversely sinusoidal patterns superimposed on a more than 50% flat tracing were predictive of fetal compromise and neonatal distress in 100% of the cases. These results allow to advocate the use of 'non-stressed' antepartum fetal heart rate monitoring, as a reliable test in the management of high risk pregnancies.

Female↗
PubMed2001

Evaluation of ventricular myocardial velocities and heart motion of the fetal heart by tissue Doppler image.

UNLABELLED: Fetal echocardiogram has developed into a reliable tool for prenatal diagnosis of congenital heart disease. It is also used to evaluate ventricular function. Recently, Tissue Doppler Imaging (TDI) has been introduced to evaluate ventricular functions especially in ischaemic heart disease. The objective of this study was to evaluate myocardial velocities and heart motions of the normal fetal heart by using TDI. The TDI was preformed in 28 fetal hearts with a gestational age of 20-35 wks (Mean 29 +/- 3.7 wks) to evaluate myocardial velocities and heart motion. The Toshiba, Power Vision, machine with 3.75 and 5 MHz transducers was used with an appropriate setting of colour-coded tissue velocities. The apical four chamber and apical or parasternal long axis views were the standard planes for measuring myocardial velocities and evaluating the heart motions. The results showed the myocardial velocities of the posterior wall of the left ventricle during the early, mid, and late systolic phases were 1.5 +/- 0.2, 2.1 +/- 0.9, and 1.0+0.5 cm/sec and early, mid, and late diastolic phases were 1.3 +/- 0.7, 1.9 +/- 0.8, and 1.1 +/- 0.7 cm/sec respectively. The myocardial velocity of the anterior wall of the right ventricle during the early, mid, and late systolic phases were 1.7 +/- 0.9, 1.7 +/- 0.6, and 1.0 +/- 0.6 cm/sec and early, mid, and late diastolic phases were 1.1 +/- 0.6, 1.8 +/- 0.7, and 1.5 +/- 1.0 cm/sec respectively. The myocardial velocity of the interventricular septum could not be measured due to the abnormal septal motion and the total fetal heart movement during the cardiac cycle. The fetal heart had anterior displacement during systole and posterior translation during diastole and also had counter-clockwise rotation during the systolic phase. CONCLUSION: Using the TDI to evaluate myocardial velocities of the fetal heart is limited by the angle of ultrasound beam and the total fetal heart motion. The fetal heart movement is similar to the newborn or young adult heart.

Adult↗
PubMed1985

Limitations of autocorrelation in fetal heart rate monitoring.

Fetal heart rate monitors that use autocorrelation of the ultrasonic fetal signal usually produce a cleaner fetal heart rate record than that obtainable with conventional ultrasonic fetal monitors. However, since the autocorrelation function will emphasize any periodic signal originating from the fetus or the mother, in clinical situations the resultant fetal heart rate tracing may contain spurious data. To illustrate the limitations of the autocorrelation technique in fetal monitoring, we compared the autocorrelated ultrasound fetal heart rate records from 23 patients in active labor with the simultaneously recorded direct scalp fetal electrocardiogram tracings. The results indicate that every hour of recording contained, on the average, five instances in which data were missing (range, 0 to 13), four in which data were added (range, 0 to 23), and seven instances in which data were absent for greater than 1 minute (range, 0 to 26). The potential problem of misinterpretation of autocorrelated fetal heart rate data is discussed.

Electrocardiography↗