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PubMedDate not supplied

Periodic fetal heart rate decelerations during 6 hours' hypoxemia induced in goats.

OBJECTIVE: To determine if fetal heart rate (FHR) decelerations periodically occur with uterine contractures during 6 hours' induced hypoxemia in goats. METHODS: In five chronically catheterized goat fetuses at 125-130 days' gestation, incidence of FHR decelerations was compared between 6 hours' control time and 6 hours' induced hypoxemia with two-way ANOVA and Duncan's multiple range test. Three other fetuses were used as controls for circadian rhythm. RESULTS: Fetal PaO2 was significantly decreased from 26.1 to 16.3 mmHg without acidemia. During hypoxemia, 42 decelerations were induced along with 5 initial decelerations during the acute phase hypoxemia. Incidence of decelerations increased significantly from 0.07 +/- 0.15 per hour in 6-hour controls to 1.40 +/- 0.28 per hour during 6 hours' induced hypoxemia. Short-term variability and long-term variability of the 42 decelerations were significantly increased. These variabilities were also increased during the 5 initial decelerations. Frequency of uterine contractures did not change during hypoxemia. There was an observable association of FHR decelerations with uterine contractures during hypoxemia. CONCLUSION: Fetal heart rate decelerations occurred periodically in association with uterine contractures during induced 6 hours' hypoxemia, which were characterized by slow onset and recovery with increases in variability.

Animals↗
PubMed1986

[Prognostic significance of single decelerations occurring in the antenatal CTG].

Within systematic fetal supervision by CTG of the risk pregnancies sometimes single decelerations of variable type are observed. Most they didn't repeat. In the majority of the cases in follow up pregnancy the child will be born spontaneously without complications. In a lot of other cases, however, there appears fetal distress. For prognostic statistical evaluation of antenatal decelerations we watched prospectively the following groups: 1.43 cases with severe antenatal variable decelerations, 2.39 cases with mild antenatal variable decelerations, 3.88 cases without antenatal decelerations. - The appearance of severe decelerations was followed by fetal distress in 42%, by perinatal death in 12%, and by caesarean delivery in 40%. Fetal prognosis in this group is significantly more unfavourable than in the two other groups with mild decelerations (fetal distress 15%, caesarean section 23%, no fetal loss) or without decelerations (fetal distress 13%, caesarean section 10%, no fetal loss). - Single severe decelerations in antenatal CTG must be evaluated as a symptom of high fetal risk.

Bradycardia↗
PubMed2001

Short early filling deceleration time on day 1 after acute myocardial infarction is associated with short and long term left ventricular remodelling.

OBJECTIVE: To assess the relations between early filling deceleration time, left ventricular remodelling, and cardiac mortality in an unselected group of postinfarction patients. DESIGN AND PATIENTS: Prospective evaluation of 131 consecutive patients with first acute myocardial infarction. Echocardiography was performed on day 1, day 2, day 3, day 7, at three and six weeks, and at three, six, and 12 months after infarction. According to deceleration time on day 1, patients were divided into groups with short (< 150 ms) and normal deceleration time (>/= 150 ms). SETTING: Tertiary care centre. RESULTS: Patients with a short deceleration time had higher end systolic and end diastolic volume indices and a higher wall motion score index, but a lower ejection fraction, in the year after infarction. These patients also showed a significant increase in end diastolic (p < 0.001) and end systolic volume indices (p = 0.007) during the follow up period, while ejection fraction and wall motion score index remained unchanged. In the group with normal deceleration time, end diastolic volume index increased (p < 0.001) but end systolic volume index did not change; in addition, the ejection fraction increased (p = 0.002) and the wall motion score index decreased (p < 0.001). One year and five year survival analysis showed greater cardiac mortality in patients with a short deceleration time (p = 0.04 and p = 0.02, respectively). In a Cox model, which included initial ejection fraction, infarct location, and infarct size, deceleration time on day 1 was the only significant predictor of five year mortality. CONCLUSIONS: A short deceleration time on day 1 after acute myocardial infarction can identify patients who are likely to undergo left ventricular remodelling in the following year. These patients have a higher one year and five year cardiac mortality.

Adult↗
PubMed2004

The effects of enforced, rapid deceleration on performance in a multiple sprint test.

The nature of multiple sprint sports such as soccer, hockey, and rugby is such that deceleration plays an important part in the movement patterns of players during a game and training. The purpose of this study was to investigate the effect of deceleration on fatigue during repeated sprint efforts. A group of 18 elite field hockey players (all men) performed a running repeated sprint ability test (6 x 40 m using maximal effort and departing every 30 seconds). In one condition, there was no deceleration zone, and in the second condition, the test had a deceleration component (rapid deceleration to a stop within 6 m of the end of each sprint). Sprint times under each condition were compared using a repeated-measures analysis of variance. No significant difference was seen between the 2 conditions for mean sprint times (p > 0.05) or for the mean fatigue index (p > 0.05). However, results showed a divergent trend, and further analysis extrapolating the data for an increased number of sprints showed that a significant difference (p < 0.05) would have been seen at the 11th sprint. Although this study found that the deceleration zone had little effect on the 6-sprint protocol, it was clear that the deceleration component would have shown an effect, giving rise to greater fatigue and slower sprint times, if the number of sprints had been increased. The implications are that deceleration training should be introduced into general fitness training programs for those competing in multiple sprint sports.

Adult↗
PubMed1975

Clinical significance of fetal heart rate patterns during labor. II. Late decelerations.

Among a population of high-risk patients in labor who had continuous "direct" electronic monitoring, 147 presented late decelerations and 598 had no decelerations at the time the first stage was completed, or a cesarean section decided upon. A variety of clinical aspects of mother and fetus were analyzed, considering some alterations observed in the FHR pattern. Apgar scores were lower among decelerations, and there was a negative correlation between these two. Maternal pathology, other than PRM, was higher among decelerations and these required enhancement more often. There was very high association with tachycardia, saltatory, and fixed baseline among decelerations, and these infants were very often distressed and born depressed. Within the group of decelerations, small fetuses had lower Apgar scores. There was a negative correlation between number of decelerations and Apgar score. The small fetuses had a high incidence of tachycardia and fixed baseline, saltatory being almost absent. Their neonatal outcome was poor. A comparison of fetal response to distress was done considering age of gestation (premature, term, and postmature) and found to be different. The mechanisms involved in late deceleration are discussed, reviewing the published experimental work. When interpreting FHR patterns, age of gestation should be one of the most important considerations.

Apgar Score↗
PubMed1992

The accuracy of auscultatory detection of fetal cardiac decelerations: a computer simulation.

To evaluate current practices of auscultation for the detection of decelerations, we used a computer to generate contractions and late decelerations and perform the counting. The baseline rate ranged from 110 to 180 beats/min. The duration of the deceleration ranged from 1 to 2 minutes, and the amplitude of the deceleration ranged from 10 to 90 beats/min. The onset of the decelerations ranged from 0.4 to 0.7 of the length of the contraction. Counting was begun at 80%, 100%, and 120% of the contraction length. The duration of counting varied between 15 and 60 seconds. A multicount algorithm obtained three 10-second counts separated by 5 seconds. Results were classified by the ability to detect rates below 120, 100, or 80 beats/min (threshold determination) or 20 and 25 beats/min below the baseline rate (subtraction determination). The baseline rate and deceleration amplitude had the greatest effect on accuracy. The higher the baseline rate and the smaller the deceleration amplitude, the less accurate was detection. Multiple counts were more accurate than the single-count strategy, and subtraction detection was more accurate than threshold detection. The effects of counting error are briefly described. This model, which requires clinical confirmation, nevertheless emphasizes the potential inaccuracies of many popular schemes of auscultatory surveillance, even for the detection of prolonged or sustained decelerations. Certain modifications of auscultatory practice may improve the accuracy of this technique.

Computer Simulation↗
PubMed1990

Individual differences in resting heart rate and spontaneous electrodermal activity as predictors of attentional processes: effects on anticipatory heart rate deceleration and task performance.

The present study was concerned with the question of whether tonic resting heart rate (HR) and resting spontaneous electrodermal activity account for the association between anticipatory HR deceleration and task performance in a choice reaction time (RT) task with a fixed foreperiod. The task employed (a varied mapping paradigm) differed from simple RT tasks especially with regard to processing and attention demands. Subjects were required to determine as quickly and accurately as possible whether a 'complex' probe, presented for 80 ms, was identical or not to one of two distinct memory items, presented at the onset of each trial. Reaction times as well as accuracy of responses were determined. Additionally, reaction time and error data were synthesized to obtain a joint measure of response behaviour. The results of the present study were indicative of a reliable anticipatory HR deceleration extended over the last seconds preceding the probe stimulus. In agreement with previous findings, the HR deceleration grew stronger over blocks of trials and was sensitive to detection requirements, i.e. probe complexity. Furthermore, HR deceleration was related to task performance. Subjects with stronger decelerations (below the median on mean deceleration) exhibited a more impulsive (fast-inaccurate) and subjects above the median a more reflective (slow-accurate) response style. The effect was mainly due to a significant difference in RT. Further results indicated that the relationship between anticipatory deceleration and RT performance was especially due to the response behaviour of one group of subjects. Subjects above the median of resting HR and resting spontaneous electrodermal activity behaved in a prominent reflective manner and also displayed the lowest foreperiod deceleration. Results were discussed in terms of differences in the regulation or control of attentional processes.

Adult↗
PubMed2002

An early predictor of left ventricular remodeling after reperfused anterior acute myocardial infarction: ratio of peak E wave velocity/flow propagation velocity and mitral E wave deceleration time.

Several studies have demonstrated that the ratio of peak E wave velocity/flow propagation velocity (E/FPV) using color M-mode Doppler echocardiography and the mitral E wave deceleration time make it possible to estimate left ventricular filling pressure. Recent studies have indicated that deceleration time can predict left ventricular dilation after acute myocardial infarction. The purpose of this study was to determine whether the early assessment of deceleration time and E/FPV could predict left ventricular dilation after acute myocardial infarction. We studied 55 patients with first anterior acute myocardial infarction who underwent successful coronary angioplasty by two-dimensional (2-D) Doppler echocardiography within 12 hours and at 1 and 6 months after reperfusion. Patients were divided into three groups according to deceleration time and E/FPV immediately after reperfusion: (1). restrictive filling (deceleration time < 140 msec and E/FPV > or= 2.0), (2). elevated filling pressure (deceleration time >or= 140 msec and E/FPV >or= 2.0), (3). and normal filling pressure (deceleration time >or= 140 msec and E/FPV < 2.0). The end-diastolic volume index (EDVI) was similar in the three groups immediately after reperfusion. EDVI in the groups with restrictive filling and elevated filling pressure was significantly greater than that in the group with normal filling pressure at 6 months (93 +/- 11 and 89 +/- 16 vs 59 +/- 11 ml/m(2), respectively; P < 0.0001). E/FPV shows a better correlation with the change in EDVI at 6 months than deceleration time (r = 0.77; P < 0.0001 and r = - 0.46; P < 0.001, respectively). The early measurement of E/FPV provides a simple and accurate means for predicting left ventricular dilation after acute myocardial infarction.

Analysis of Variance↗
PubMed2001

Lack of relationship between variable decelerations during reactive nonstress tests and oligohydramnios.

We sought to prospectively determine the value of variable and lambda decelerations noted during nonstress tests in predicting oligohydramnios and perinatal outcome. On the same day as having had reactive nonstress tests, 651 women underwent obstetrical ultrasound examinations for amniotic fluid index (AFI). Lambda and variable fetal heart rate decelerations were identified on sets of otherwise-reactive nonstress tests. Those with variable decelerations composed group 1; those without variable decelerations composed group 2. Demographic, perinatal outcome, and AFI data were compared, and group 1 inclusion criteria were varied. There were 200 nonstress tests in group 1 and 490 in group 2. There was a small difference between groups in maternal age (1.2 years, p = 0.02) and gestational age (0.8 weeks, p = 0.01), but no differences in gravidity, parity, race, or indications for testing (p >0.05). Oligohydramnios was present in 14.5% in group 1 and in 13.3% of group 2 (p = 0.68). In the cases of amniotic fluid index <8 cm, depth and duration of the variable decelerations did not correlate with AFI (R2 = 0.11, p = 0.09). Variable decelerations were associated with intrapartum "fetal distress," but lambda decelerations did not correlate with any outcome. Variable decelerations on an otherwise-reactive nonstress test did not correlate with amniotic fluid volume and were not cause for intervention in this study.

Adult↗
PubMed2000

Middle cerebral artery Doppler velocimetric deceleration angle as a predictor of fetal anemia in Rh-alloimmunized fetuses without hydrops.

OBJECTIVE: The purpose of this study was to evaluate the screening performance of a new middle cerebral artery Doppler velocimetric index for the prediction of fetal anemia. STUDY DESIGN: Doppler velocimetry of the middle cerebral artery was performed before cordocentesis in 24 Rh-alloimmunized fetuses without hydrops on 52 occasions. The angle between the line describing the average slope during the diastolic phase of the cardiac cycle and the vertical, the middle cerebral artery standardized deceleration angle, was measured. The deceleration angle values were expressed in multiples of the median for gestational age. The screening performances of deceleration angle for the prediction of anemia (difference between expected mean hemoglobin level and measured value >/=2 g/dL) and severe anemia (hemoglobin deficit >/=5 g/dL) were determined. RESULTS: The mean (+/-SD) gestational age at cordocentesis was 28.6 +/- 5.7 weeks' gestation. The risk of fetal anemia increased with decreasing deceleration angle values. The sensitivity and false-positive rate for the detection of anemia in cases with no previous transfusions (one measurement per patient) were 72.0% and 13.3%, respectively; among those with one previous transfusion the values were 90.0% and 0.0%, respectively. For severe anemia the corresponding values were 100% and 0%, respectively, among those with no previous transfusions and 100.0% and 16.7%, respectively, among those with one previous transfusion. There was no risk of severe anemia when the angle was >0.9 multiples of the median. The risk of anemia was significantly reduced with an angle greater than the median for gestational age (deceleration angle >1.0 multiples of the median; relative risk, 0.09; 95% confidence interval, 0.02-0.37). The risk was significantly increased with an angle less than the median for gestational age (deceleration angle <1.0 multiples of the median; relative risk, 30.0; 95% confidence interval, 5.9-158.4). CONCLUSION: The risk of fetal hydrops is remote in the absence of severe anemia. With a new Doppler velocimetric index in the middle cerebral artery the risk of severe anemia was found to be low when the deceleration angle was >0.9 multiples of the median. Anemia can also be predicted with this index. The high sensitivities and acceptable false-positive rates support the potential clinical applicability of the method to reduce the reliance on cordocentesis in Rh alloimmunization. Our findings appear to validate the utility of the deceleration angle for the prediction of fetal anemia.

Anemia↗
PubMed2002

Late-onset fetal cardiac decelerations associated with fetal breathing movements.

BACKGROUND: While late decelerations are regarded as signs of fetal hypoxemia, fetal breathing movements (FBM) associated with late decelerations invariably have normal outcomes. Could late decelerations sometimes represent FBM? MATERIALS AND METHODS: Six patients between 37 and 42 weeks' gestation with 'late decelerations' associated with FBM (by ultrasound or tocodynamometer) during ante- or intrapartum monitoring were evaluated. Three were at high risk (diabetes, postdates, intrauterine growth restriction) and three were at low-risk. RESULTS: 'Late decelerations' arose in previously reassuring tracings. Oxygen or positional change had no effect. The decelerations were variable in length and shallow, and contained increased variability. Normal baseline rate and variability were maintained after the deceleration. Neonatal outcomes were normal. CONCLUSION: 'Late decelerations' as described are associated with normal outcome and may represent FBM. This understanding may reduce unnecessary interventions.

Bradycardia↗
PubMed1998

Is dobutamine-induced sinus node deceleration a marker of significant stenosis of the right coronary artery?

STUDY OBJECTIVES: Sinus node deceleration during exercise is a highly specific marker for significant stenosis of the right coronary artery. Prior studies of dobutamine-induced sinus node deceleration have contained relatively few patients, and the purpose of this study was to determine if sinus node deceleration is an accurate marker of right coronary artery disease in a much larger study population. DESIGN: Dobutamine stress echocardiography was performed in a cohort of patients, and submaximal exercise testing and coronary angiography were performed in most of the patients. SETTING: A university hospital. PATIENTS AND INTERVENTIONS: Dobutamine stress echocardiography was performed in 757 patients, and symptom-limited submaximal treadmill ECG was also performed in 571 of those patients. Sinus node deceleration was defined as a decrease in the heart rate at peak stress compared with that at the previous stage. Coronary angiography was performed in 631 patients, 184 of whom were found to have significant right coronary artery stenosis. MEASUREMENTS AND RESULTS: The prevalence of dobutamine-induced sinus node deceleration (54 [7%] of 757 patients) was significantly higher than that induced during treadmill ECG (3 [0.5%] of 571 patients; p<0.001). The prevalence of inferior ischemia by echocardiography did not differ between patients with dobutamine-induced sinus node deceleration (26%) and those without (30%). There was also no significant difference in the prevalence of right coronary artery stenosis between the two groups (27% vs 29%). The specificity of dobutamine-induced sinus node deceleration for detecting significant stenosis of the right coronary artery (92%) was higher than that of echocardiography (84%; p<0.00), but the positive predictive value was lower (28% vs 64%; p<0.001). CONCLUSIONS: Although sinus node deceleration during dobutamine stress echocardiography is a relatively more common finding, it does not always accompany significant stenosis in the right coronary artery. The mechanism for its induction is postulated to be vagal activation caused by multiple factors.

Adrenergic beta-Agonists↗
PubMed1976

Evaluation of the fetal state by automatic analysis of the heart rate. 2. Deceleration areas and umbilical artery blood pH.

Fetal heart rate (FHR) deceleration areas were studied to obtain by objective measurement of the FHR, their prognostic value of the new-born state. 1. There is a reasonably good correlation between FHR deceleration areas and UApH (Tab. II). Such a correlation was found by SHELLEY and TIPTON [6] for the whole deceleration area, and by TOURNAIRE et al. [10] for areas divided in a slightly different way. The correlation coefficients between FHR deceleration areas and Apgar score at 1 minute are within a close range of those of the FHR deceleration area and UApH (Tab. I and II). 2. According to the time relationship between deceleration areas and uterine contractions the best correlation coefficient was obtained surprisingly for total, followed by residual and then simultaneous areas. These results agree with those of SHELLEY and TIPTON [6] suggesting that in practice a simple measurement of the whole deceleration area, regardless of the uterine contractions is a sufficient method in evaluating FHR patterns. 3. The special purpose computer built by the BAUDELOCQUE research group can be used on-line, thus in clinical practice. It was not the case for the manual method [4] or the method using a large programmed computer [10]. 4 The evaluation of deceleration areas appears to have several advantages: 1. It provides objective measurements. 2. The unit used is independant of factors such as display speed or scale of the strip-chart. 3. The data is reduced: A few numbers replace the long descriptions of the usual clinical classifications.

Apgar Score↗
PubMed2004

Relationships between fore- and hindlimb ground reaction force and hoof deceleration patterns in trotting horses.

REASONS FOR PERFORMING STUDY: The transmission of shockwaves following hoof impact is proposed to be one major source of stress to the limb. In the forelimb, there are indications that the period of horizontal deceleration of the hoof is related to the attenuation of shockwaves. In the hindlimb, information about the hoof deceleration has been lacking. OBJECTIVE: To compare hoof deceleration patterns between the fore- and hindlimbs. METHODS: Seven Standardbreds were trotted by hand over a force plate covered with sand, with triaxial accelerometers mounted on the fore and hind hooves. Variables representative of decelerations (first 2 main vertical deceleration peaks; characteristic minimum and maximum values in the craniocaudal deceleration; hoof braking time) and ground reaction forces (vertical loading rates; maximum and the following local minimum of the craniocaudal force) of the initial part of the stance phase, and the differences between individual fore- and hindlimb time and amplitude variables were used for statistical analyses. RESULTS: Force plate data showed significantly greater vertical loading rate (mean +/- s.d. 6.5 +/- 5.9 N/sec) and horizontal loads (190.4 +/- 110.2 N) in the forelimb than the hindlimb, but the parameters from accelerometer data showed no significant differences. CONCLUSIONS: No significant difference was found in the hoof deceleration, but the deceleration curves displayed a common pattern that described in detail the kinematics of the fore and hind hooves during the initial period of hoof braking. POTENTIAL RELEVANCE: These results contribute to further knowledge about the characteristics of these potential risk factors in the development of subchondral bone damage in the horse. Further studies are required on the influence of hoof braking pattern at higher speed, different shoeing and ground surfaces with different properties.

Analysis of Variance↗
PubMed1994

Changes in umbilical arterial and venous blood flow velocity waveforms during late decelerations of the fetal heart rate.

OBJECTIVE: To compare umbilical arterial and venous Doppler velocity waveforms during labor in fetuses with normal heart rate tracings and fetuses with late decelerations. METHODS: During labor, umbilical arterial and venous Doppler flow velocity waveforms were obtained between and during contractions in 20 fetuses (ten with normal heart rate tracings and ten with late decelerations). The umbilical arterial systolic-diastolic (S/D) velocity ratios were compared, and umbilical venous velocities were examined for the presence or absence of venous pulsations. RESULTS: Fetuses with late decelerations had a significant increase in the umbilical arterial S/D ratio between contractions compared to normal fetuses (2.43 +/- 0.74 versus 1.56 +/- 0.27, P = .003). There was no significant difference in S/D ratios obtained between contractions compared with those obtained during contractions in either the normal or late deceleration group. Umbilical venous pulsations were significantly more common (90 versus 0%, P < .00001) during contractions in fetuses with late decelerations; umbilical venous pulsations were not seen in these fetuses between contractions and were not present at any time in fetuses with normal heart rate tracings. CONCLUSIONS: Increased umbilical arterial velocity ratios and the presence of umbilical venous pulsations during contractions in fetuses with late decelerations suggest that the cardiovascular pathophysiology of late decelerations involves changes in placental resistance as well as cardiac performance. The presence of umbilical venous pulsations during late decelerations is consistent with the hypoxic fetal cardiovascular changes (hypertension and myocardial depression) previously reported from animal studies.

Apgar Score↗
PubMed2005

Deceleration affects anticipatory and reactive components of triggered postural responses.

Understanding the physiological and psychological factors that contribute to healthy and pathological balance control in man has been made difficult by the confounding effects of the perturbations used to test balance reactions. The present study examined how postural responses were influenced by the acceleration-deceleration interval of an unexpected horizontal translation. Twelve adult males maintained balance during unexpected forward and backward surface translations with two different acceleration-deceleration intervals and presentation orders (serial or random). "SHORT" perturbations consisted of an initial acceleration (peak acceleration 1.3 m s(-2); duration 300 ms) followed 100 ms later by a deceleration. "LONG" perturbations had the same acceleration as SHORT perturbations, followed by a 2-s interval of constant velocity before deceleration. Surface and intra-muscular electromyography (EMG) from the leg, trunk, and shoulder muscles were recorded along with motion and force plate data. LONG perturbations induced larger trunk displacements compared to SHORT perturbations when presented randomly and larger EMG responses in proximal and distal muscles during later (500-800 ms) response intervals. During SHORT perturbations, activity in some antagonist muscles was found to be associated with deceleration and not the initial acceleration of the support surface. When predictable, SHORT perturbations facilitated the use of anticipatory mechanisms to attenuate early (100-400 ms) EMG response amplitudes, ankle torque change and trunk displacement. In contrast, LONG perturbations, without an early deceleration effect, did not facilitate anticipatory changes when presented in a predictable order. Therefore, perturbations with a short acceleration-deceleration interval can influence triggered postural responses through reactive effects and, when predictable with repeated exposure, through anticipatory mechanisms.

Acceleration↗
PubMed2003

Spontaneous fetal heart rate deceleration: an ominous sign for fetal outcome.

BACKGROUND: The aim of this study was to establish the prognostic import of spontaneous fetal heart-rate deceleration, a sign of fetal distress. METHODS: This retrospective study enrolled 169 patients with fetal heart-rate deceleration treated at Shin-Kong Wu Ho Su Memorial Hospital from 1 January 1998 to 24 November 2000. Reviewed variables included type of fetal heart-rate irregularity (including early, variable, late, and spontaneous variants), neonatal outcome, Doppler results, gestational age and weight at birth, and amniotic fluid index. RESULTS: The spontaneous form of fetal heart-rate deceleration was determined for 11 of the 169 patients (6.5%) diagnosed with fetal heart-rate deceleration, with a 5-min Apgar score below 7 observed for 5 (45.5%) of these subjects, and neonatal complications for 9 (81.8%). Mean gestational age was 32.2+/-3.8 weeks; mean birth weight was 1,560+/-723.9 g. Spontaneous deceleration has a sensitivity of 29%, specificity of 99%, positive predictive value of 81.8%, and negative predictive value of 86.1%. CONCLUSION: Although of the different fetal heart-rate deceleration types the spontaneous variant has the lowest incidence rate, the complication and mortality rates are highest and it is also associated with lower birth weight and higher incidence of pre-term labor. Failure of the fetus to cope with the compromised placental flow and uterine compression resulting from oligohydramnios may be fundamental to the etiology of spontaneous fetal-heart rate deceleration. Once diagnosed, Doppler ultrasound may be used to assess placental-vessel flow. Emergency treatment may be mandatory if deterioration is noted.

Adult↗
PubMed1979

A study of variable decelerations in association with other heart rate patterns during monitored labor.

A review of 1,011 consecutive intrapartum heart rate tracings yielded 37.3% with some degree of variable deceleration pattern. No differences in Apgar score distribution were observed in the presence of uncomplicated variable deceleration pattern when compared to those tracings marked normal. However, the presence of variable decelerations in association with other heart rate patterns resulted in lower mean Apgar scores at 1 and 5 minutes, which were significantly different from those of the fetal heart rate (FHR) normal group. Mean Apgar scores at 1 and 5 minutes were significantly different from normal when variable decelerations were noted in the presence of tachycardia and loss of variability. Mean Apgar scores were lower when bradycardia (prolonged episodes of heart rate less than 120 bpm) was present in the record when compared to normal, but the presence of variable decelerations with bradycardia did not result in different mean scores. The presence of baseline changes with loss of variability and variable decelerations appeared to result in the lowest mean scores. When bradycardia or tachycardia occurred in exclusive association with variable decelerations, the percentage of depressed newborn infants was relatively high.

Apgar Score↗