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PubMed2000

Noninvasive indexes of left atrial diastolic function in hypertrophic cardiomyopathy.

OBJECTIVES: Our goal was to noninvasively assess left atrial diastolic function and its relation to the impaired left ventricular filling in patients with hypertrophic cardiomyopathy. METHODS AND RESULTS: We studied 34 patients with hypertrophic cardiomyopathy, 26 patients with secondary forms of left ventricular hypertrophy (aortic stenosis, fixed subaortic stenosis, hypertension), and 21 control subjects. Left atrial diastolic function was assessed by measuring acceleration time (SAT), deceleration time (SDT), and the EF (mean deceleration rate) slope of the pulmonary venous flow systolic wave (SW). Left ventricular diastolic function assessed by transmitral Doppler included peak early left ventricular and peak atrial filling velocities, the ratio of early-to-late peak velocities, isovolumic relaxation time, deceleration time, and EF slope. In patients with hypertrophic cardiomyopathy, acceleration time was significantly reduced (P<.05), deceleration time was significantly prolonged (P<.0001), and EF slope was significantly reduced (P<.01). These indexes were similar among the other two groups. No statistically significant difference existed between the subgroups of hypertrophic cardiomyopathy in the above indexes. Patients with hypertrophic cardiomyopathy and secondary forms of left ventricular hypertrophy had evidence of left ventricular diastolic dysfunction. In patients with hypertrophic cardiomyopathy, no correlation existed between left atrial and left ventricular diastolic function indexes (r = -0.26 to 0.33). CONCLUSIONS: Echocardiographic indexes of left atrial relaxation and filling are abnormal in patients with hypertrophic cardiomyopathy but not in secondary forms of left ventricular hypertrophy. These indexes are abnormal in all forms of hypertrophic cardiomyopathy irrespective of left ventricular outflow tract obstruction and distribution of hypertrophy; they are not solely attributable to left ventricular diastolic dysfunction. The above may imply that hypertrophic cardiomyopathy is a cardiac myopathic disease that involves the heart muscle as a whole, irrespective of distribution of hypertrophy and obstruction.

Adolescent↗
PubMed2001

Abnormal fetal heart rate tracing patterns during the first stage of labor: effect on perinatal outcome.

OBJECTIVE: The purpose of this study was to evaluate perinatal outcomes of infants who had pathologic fetal heart rate tracings during the first stage of labor, in comparison with pregnancies with normal tracings. STUDY DESIGN: The perinatal outcomes of 301 infants born at 37 to 42 weeks of gestation with pathologic fetal heart rate patterns during the first stage of labor were compared with 300 infants with normal fetal heart rate tracing patterns. The data were collected prospectively. Tracings were interpreted with the use of the National Institute of Child Health and Human Development fetal heart rate monitor guidelines. RESULTS: Hydramnios (odds ratio, 7.68; 95% CI, 1.75%-33.63%), oligohydramnios (odds ratio, 2.74; 95% CI, 1.01%-7.39%), and the presence of meconium-stained amniotic fluid (odds ratio, 1.91; 95% CI, 1.03%-3.3%) were independent factors that were associated with pathologic fetal heart rate monitoring during the first stage of labor in a multivariable analysis. The occurrences of umbilical arterial pH of <7.20, a 1-minute Apgar score of <7, a base deficit of 12 mmol/L or higher, and operative deliveries were significantly higher in the study group as compared with subjects with normal fetal heart rate monitoring. Late decelerations and severe variable decelerations (<70 bpm) during the first stage of labor were independent risk factors (odds ratio, 17.5; 95% CI, 1.61%-185.7% and odds ratio, 3.9; 95% CI, 1.36%-11.7%, respectively) that were associated with fetal acidosis (determined by both pH of <7.2 and a base deficit of 12 mmol/L or higher) in a multiple logistic model, controlled for hydramnios, oligohydramnios, meconium-stained amniotic fluid, augmentation by oxytocin, nulliparity, duration of first stage of labor, and birth weight. CONCLUSION: The operative delivery rate was higher among patients with abnormal first-stage fetal heart rate patterns. Late decelerations and severe variable decelerations were significant factors associated with fetal acidosis.

Apgar Score↗
PubMed2002

Optimal control strategies under different feedback schedules: kinematic evidence.

Two experiments were conducted in which participants (N = 12, Experiment 1; N = 12, Experiment 2) performed rapid aiming movements with and without visual feedback under blocked, random, and alternating feedback schedules. Prior knowledge of whether vision would be available had a significant impact on the strategies that participants adopted. When they knew that vision would be available, less time was spent preparing movements before movement initiation. Participants also reached peak deceleration sooner but spent more time after peak deceleration adjusting limb trajectories. Consistent with those findings, analysis of spatial variability at different points in the trajectory indicated that variability increased up to peak deceleration but then decreased from peak deceleration to the end of the movement.

Biomechanical Phenomena↗
PubMed1990

Mechanisms underlying accuracy in fast goal-directed arm movements in man.

This study investigated how accuracy is attained in fast goal-directed arm movements. Subjects were instructed to make arm extension movements over three different distances in random order, with and without visual feedback. Target width was varied proportionally with distance. Movement time was kept as short as possible, but there were well-defined limits with respect to accuracy. There appeared to be a large relative variability (variation coefficient [VC]) in the initial acceleration. The VC in the distance the hand moved during the acceleration phase was much smaller. This reduction was accompanied by a strong negative correlation between the initial acceleration and the duration of the acceleration phase. Further, the VC in the total distance moved was less than the VC in the distance moved during acceleration. This result indicates asymmetry between the acceleration and the deceleration phase. This is confirmed by the negative correlation between the distance the hand moved during acceleration and the distance it moved during deceleration. Withdrawal of visual feedback had a significant effect on movement accuracy. No differences were found in the parameters of the acceleration phase in the two feedback conditions, however. our results point to the existence of a powerful variability compensating mechanism within the acceleration phase. This mechanism seems to be independent of visual feedback; this suggests that efferent information (efference copies) and/or proprioceptive information is/are responsible for the timing of agonist and antagonist activation. The asymmetry between the acceleration and deceleration phase contributes to a reduction in the relative variability in the total distance moved. The fact that the withdrawal of visual feedback affected movement variability only during the deceleration phase indicates that visual information is used in the adjustment of antagonist activity.

Journal Article↗
PubMed1993

Error processing in pointing at randomly feedback-induced double-step stimuli.

Two experiments were conducted to determine the spatial and temporal organization of the arm trajectory in human subjects as they pointed to single- and double-step target displacements. Subjects pointed either without (Experiment 1) or with (Experiment 2) vision of their moving hand throughout the trial. In both experiments, target perturbation occurring in double-step trials was clearly perceived by the subjects and was randomly introduced either at the onset or at peak velocity of hand movement. Regardless of whether or not visual reafference from the pointing hand was available, subjects corrected the trajectory of their moving hand to accommodate the double-step. Moreover, asymmetrical velocity profiles were observed for responses to both types of target, with or without vision of the moving hand. The acceleration phase was a fixed pattern independent of the type of step stimulation. However, a clear dissociation, both in the deceleration phase and accuracy of responses to double-step targets, emerged according to the timing of target perturbation. When targets were perturbed at the onset of hand movement, subjects modulated the deceleration phase of their response to compensate for 88 to 100% of the second target displacement. In contrast, when targets were perturbed at peak velocity of hand movement, subjects were unable to modulate the deceleration phase adequately and compensated for only 20 to 40% of the perturbation. These results suggest that motor error is dynamically evaluated during the acceleration phase of a movement toward a perturbed target, allowing amendments to the trajectory to be performed during the deceleration phase. This main corrective process appears to be basically independent of visual reafference from the moving hand.

Journal Article↗
PubMed1990

Hemispheric asymmetry, cardiac response, and performance in elite archers.

Previous sport research on elite athletes has shown systematic changes in psychophysiological measures, such as heart rate (HR) deceleration and hemispheric asymmetries in EEG activity, in the few seconds prior to executing a motor response. These changes are believed to be due to a more focused attention on the external environment. Using archery (an attentive state), this investigation was designed to examine: (a) whether hemispheric asymmetry and HR deceleration would occur during the aiming period, and (b) if they did, whether this would affect performance. HR and left and right temporal EEG were recorded from 28 right-handed elite archers for 16 shots. The results indicated that (a) there was no HR deceleration; (b) during the aiming period, EEG alpha activity formed the dominant frequency and this was significantly greater in the left than in the right hemisphere; (c) there were no significant right hemisphere EEG changes in spectral power from 3 s before the shot to arrow release, but there were significant left hemisphere increases at 10, 12, and 24 Hz; and (d) at 1 s prior to the shot, there were no significant right hemisphere spectral power differences between best and worst shots, but there were significant left hemisphere differences at 6, 12, and 28 Hz. The relationships among hemispheric asymmetry, HR deceleration, attentional processes, and shooting performance are discussed.

Adolescent↗
PubMed2001

Evaluation of fetal heart monitoring in the first stage of labor.

OBJECTIVE: To evaluate the usefulness of continuous electronic fetal heart rate (FHR) monitoring in the first stage of labor. METHODS: A total of 814 pregnant women in labor without identifiable risk factors was divided into two groups. In group A (468 cases), continuous FHR monitoring began in the earliest phase of the first stage of labor (cervical dilatation < or = 4 cm), while in group B (346 cases) it began when the cervical dilatation was > 4 cm. Initial FHR tracings were normal in all 814 cases. The fetal monitoring findings were analyzed at 10-min intervals, and comparisons were made between the two groups concerning FHR findings and their correlation with the state of the newborns. RESULTS: No significant difference was found between the two groups in the incidence of repetitive variable decelerations (1.9% and 1.7%, respectively); sporadic variable decelerations (9.2% and 8.7%, respectively); persistent repetitive late decelerations that resulted in Cesarean section (1.1% and 1.4%, respectively); or sporadic late decelerations (8.3% and 8.1%, respectively). One newborn from each group required intensive neonatal care. CONCLUSIONS: The same tracing sufficiency of fetal stress was observed in the two groups. However, the manner of labor supervision in group B seemed to be more beneficial, because of greater maternal comfort, a lower necessity for personnel, lower consumption of cardiotocographic materials and the possibility of labor induction for more women. Since fetal monitoring is widely used, it is preferable to start continuous FHR monitoring when the dilatation of the cervix approximates 4-5 cm (second phase of the first stage of labor) without risk of fetal loss.

Adolescent↗
PubMed1973

RNA synthesis and turnover during density-inhibited growth and encystment of Acanthamoeba castellanii.

Alterations in transcription that precede and accompany encystment (E) of suspension grown A. castellanii have been investigated. Comparative studies were performed on cells undergoing spontaneous E in high density stationary phase cultures or after experimental induction of E at low cell densities by deprivation of nutrients in exponential growth. Onset of growth deceleration at high cell densities was accompanied by an increase in the cellular RNA. The maximum RNA content occurred in cells at stationary phase and subsequently declined with the appearance of cysts in the cultures. On the contrary, the RNA content in cells whose growth was immediately terminated by experimental E induction remained at a constant exponential level through 5 h postinduction and then began to decline shortly before the appearance of cysts. The mature cyst formed in stationary phase cultures and after experimental E induction contained an equivalent amount of RNA ( approximately 50% of the exponential value). Comparison of the kinetics of [(3)H]uridine incorporation demonstrated that there was an abrupt reduction in the rate of uridine incorporation into RNA with onset of growth deceleration or after growth termination in experimental E induction. The reduced incorporation of uridine into RNA could not be attributed to to a reduced uptake of the isotope by the cells or an altered capacity of the cells to phosphorylate uridine. Uridine continued to be incorporated into RNA at a reduced rate in cells throughout growth deceleration, in stationary phase, and up to 12 h postexperimental induction. Considered together, these results indicate that a buildup in RNA is not necessary for induction of encystment in acanthamoeba. The accumulated RNA in stationary phase cells appears to be due to the greater reduction in the growth rate than in transcription and the absence of RNA turnover in cells during growth deceleration. Initiation of RNA turnover appears to accompany growth termination and induction of E. The results further demonstrate that the regulation of the rate of transcription is closely coordinated with the control of growth and encystment in acanthamoeba.

Animals↗
PubMed1975

Chronotropic response to acetylcholine injected into the sinus node artery of the isolated atrium of the dog.

Injection of a single bolus of acetylcholine into the sinus node artery of the isolated atrium of the dog produces a triphasic response similar to that previously observed after a single stimulus to the vagus nerves. There is an initial, brief but pronounced, cardiac deceleration followed by a brief, slight acceleration, which is then followed by a more prolonged deceleration which is of lesser magnitude than the initial deceleration. The most likely cause of the intermediate phase of cardiac acceleration is a direct effect of acetylcholine on the pacemaker cells, as it is also with the primary and tertiary phases of cardiac deceleration.

Acetylcholine↗
PubMed1997

The association between Doppler transmitral flow variables measured by transesophageal echocardiography and pulmonary capillary wedge pressure.

The association between Doppler transmitral flow variables, measured by transesophageal echocardiography (TEE), and pulmonary capillary wedge pressure (PCWP) was studied in 88 patients undergoing coronary artery surgery. The Doppler flow variables and PCWP were measured after sternotomy by blinded investigators. In the first part of the study, patients were divided into two groups according to left ventricular (LV) ejection fraction (EF): Group A, EF > 35% (n = 38) and Group B, EF < or = 35% (n = 34). In Group B, significant correlations were found between deceleration time of early filling (DCT-E) and PCWP (r2 = 0.899) and deceleration slope of early filling and PCWP (r2 = 0.692), (P < 0.001 for both). When the relationship between DCT-E and PCWP was tested prospectively in a third group of patients [Group C; EF < or = 35% (n = 16)], a close agreement between the calculated and measured PCWP (bias = -0.55 +/- 3.87 mm Hg) was noted. The sensitivity, specificity, and positive predictive value of DCT-E > or = 150 ms for PCWP < 10 mm Hg were 93.3%, 100%, and 100%, respectively. In summary, patients with decreased left ventricular systolic function undergoing coronary artery surgery demonstrated high, statistically significant, correlations between PCWP and the deceleration time or deceleration slope of early diastolic filling as measured by transesophageal Doppler echocardiography.

Age Factors↗
PubMed1997

Role of left ventricular hypertrophy in diastolic dysfunction in aged hypertensive patients.

OBJECTIVE: To evaluate the influence of left ventricular hypertrophy (LVH) on the diastolic dysfunction in older hypertensive patients. METHODS: In total 665 patients (58% men, 61% White, aged 55-80 years) with mild-to-moderate essential hypertension underwent Doppler echocardiography. Data included left ventricular dimensions, left ventricular mass index, body mass index, E- and A-wave mitral flow velocities, E:A ratio, deceleration time > 150 ms), impaired relaxation (E:A ratio < 1.0, prolonged deceleration time according to age), and restrictive physiology (E:A ratio > 2.1, deceleration time < 150 ms)]. Data were distributed according to age (50-59, 60-69, and 70-80 years). RESULTS: The overall prevalence of sex-adjusted LVH in this study was 65%. When we compared hypertensive patients with and without LVH, the E- and A-wave velocities, E:A ratio, and deceleration time were similar. Moreover, the prevalences of normal, impaired relaxation, and restrictive physiology patterns among patients with and without LVH did not differ significantly (20, 79.5, and 0.5 versus 24, 75.5, and 0.5%). When the mitral flow patterns were adjusted according to age, the impaired relaxation pattern increased further with age (to 73% during the fifth decade, 83% during the sixth decade, and 88% during the seventh decade). CONCLUSIONS: LVH is not an independent factor associated with abnormal flow patterns in hypertensive patients aged over 50 years with normal systolic contractility. The impaired relaxation is the predominant pattern of diastolic dysfunction in older hypertensive patients and increases further with aging.

Aged↗
PubMed1988

Reliability of intrapartum fetal heart rate monitoring in the postterm fetus with meconium passage.

Fifty-six postterm fetuses with intrapartum meconium passage underwent routine scalp stimulation and scalp blood sampling. Fetal heart rate (FHR) patterns were compared with blood pH. Nine fetuses (16%) had a scalp pH less than 7.20. Twenty-nine fetuses (54%) demonstrated spontaneous or induced FHR accelerations; none were acidemic. Acidemia with normal variability was found only in conjunction with severe variable decelerations, and may represent respiratory acidosis. In this group, two of nine acidemic fetuses demonstrated no decelerations (pH 7.04) or mild variable decelerations only (pH 7.19). The absence of late decelerations was not as reliable as the presence of accelerations in the prediction of fetal well-being. Thirty-three percent of the fetuses who failed to exhibit spontaneous or provoked FHR accelerations were acidemic. These findings suggest that in this high-risk group of fetuses, the absence of spontaneous FHR accelerations should be followed by an attempt to induce accelerations, scalp pH assessment, or cesarean section.

Acidosis↗
PubMed1997

Left ventricular diastolic filling changes during dipyridamole-induced ischaemia. An echo-Doppler study.

OBJECTIVE: To evaluate the usefulness of the Doppler assessment of left ventricular diastolic functioning during dipyridamole-induced ischaemia in patients with coronary artery disease (CAD). METHODS: We studied 28 patients with angiographically proven CAD [18 men, aged 62 +/- 7 years (mean +/- SD)] and 18 normal subjects (12 men, aged 59 +/- 7.5 years). Two-dimensional and transmitral flow Doppler echocardiography studies were performed at baseline and after intravenous administration of a high dose of dipyridamole (0.84 mg/kg during 10 min). Left ventricular wall motion was evaluated by two-dimensional Doppler echocardiography, with the left ventricle divided into a 16-segment model, whereas peak velocities of early and late diastolic flow, the early:late diastolic flow ratio and the deceleration rate of early diastolic flow were determined from transmitral flow Doppler echocardiography. RESULTS: Sixteen patients developed new wall-motion abnormalities (WMA), whereas the remaining 12 patients and the controls did not. Multivariate logistic regression analysis was performed to identify which of the parameters had independent diagnostic value for revealing CAD. WMA was entered at the first step and yielded a 57% sensitivity and 100% specificity; the changes in deceleration rate were entered as the second step, which improved the sensitivity to 85.5%, and reduced the specificity to 83% and raised the overall accuracy to 85% from 70% for WMA alone. More specifically, the sensitivity improved from 37.5, 63.5 and 65.5% to 62.5, 91 and 100%, respectively, for patients with one-, two- and three-vessel disease. The cut-off value of the change in deceleration rate was 7%. CONCLUSIONS: Patients could be classified as having CAD either if they developed new WMA or if the deceleration rate of early diastolic flow during dipyridamole-stress echocardiography increased by more than 7% compared with the rest value.

Case-Control Studies↗
PubMedDate not supplied

Left ventricular diastolic function assessment by tissue Doppler echocardiography in relation to hormonal replacement therapy in postmenopausal women with diastolic dysfunction.

The objective of this study was to evaluate the effect of hormone replacement therapy (HRT) regimens on left ventricular diastolic function by using mitral pulsed wave Doppler (MPWD) and tissue Doppler velocities (TDE). Seventy-eight postmenopausal women with normotensive and impaired diastolic left ventricular filling were included in the study. All the patients began a six-cycle HRT course. This formulation consisted of E2 valerate plus Medroxy progesterone acetate (MPA). Left ventricular diastolic function at rest was evaluated by M-mode, two-dimensional, MPWD and TDE in 78 postmenopausal women with normal blood pressure before the treatment for 6 months of HRT. The M-mode, two-dimensional, and MPWD parameters assessed were heart rate, systolic blood pressure, diastolic blood pressure, left ventricular mass index, ejection fraction of the left ventricle (EF), septal (IVS) and posterior wall (PW) thickness, left ventricular end-systolic (LVESD) and end-diastolic (LVEDD) diameter, left atrial diameter, peak early diastolic velocity (E), peak atrial velocity (A), E/A ratio, E acceleration time, E deceleration time, diastolic filling period, and isovolumic relaxation time (IVRT). The TDE parameters assessed were peak early diastolic velocity (E'), peak late diastolic velocity (A'), peak systolic velocity, E'/A' ratio, E' acceleration time, E' deceleration time, IVRT', and E/E' ratio. Quantitative data were analyzed using Student t test. Among the MPWD parameters, peak A velocity, E deceleration time, and IVRT significantly decreased, while peak E velocity and E/A ratio increased after a 6-month treatment. From the point of TDE parameters, E' velocity and E'/A' ratio increased, while A' velocity, E' deceleration time, E/E' ratio and IVRT' decreased. Some MPWD and TDE parameters were partially reversed after HRT. TDE velocities and especially E/E' ratio may provide better and true information of the diastolic function. TDE parameters were independent from the preload and did not produce pseudonormal pattern. HRT may cause increase in the blood volume and produce pseudonormal pattern in transmitral flow. In that case, TDE may be a beneficial method for evaluation of diastolic function.

Diastole↗
PubMed2005

Can electronic fetal monitoring identify preterm neonates with cerebral white matter injury?

OBJECTIVE: Although preterm delivery occurs in only 10% of all births, these infants are at high risk for cerebral white matter injury and constitute a third of all cerebral palsy cases. Our objective was to estimate if electronic monitoring can identify preterm fetuses diagnosed with brain injury during the neonatal period. METHODS: In this case-control study, 150 consecutive neonates with ultrasonography-diagnosed cerebral white matter injury were matched by gestational age within 7 days to 150 controls with normal head ultrasonograms. Tracings were retrieved for 125 cases (83%) and 121 controls (81%) and reviewed by 3 perinatologists blinded to outcome. Vaginal (64 cases, 72 controls) and cesarean deliveries (61 cases, 49 controls) were analyzed separately. RESULTS: There was no difference in baseline heart rate, tachycardia, bradycardia, short-term variability, accelerations, reactivity, number or types of decelerations, or bradycardic episodes between cases and controls in either the vaginal or cesarean delivery groups. For the 6 neonates with metabolic acidosis severe enough to increase the risk for long-term neurologic morbidity, there was a significant increase in baseline amplitude range less than 5 beats per minute; however, its positive predictive value in predicting severe metabolic acidosis was only 7.7%. Increasing late decelerations were associated with decreasing umbilical arterial pH and base excess, but were not significantly different in the acidosis and control groups (1.0 +/- 1.8, 0.55 +/- 1.23 late decelerations per hour, P = .39). CONCLUSION: Although decreased short-term variability and increased late decelerations are associated with decreasing umbilical arterial pH and base excess, electronic fetal monitoring is unable to identify preterm neonates with cerebral white matter injury.

Acidosis↗
PubMed2005

Confinement of a large number of antiprotons and production of an ultraslow antiproton beam.

We have used a radio frequency quadrupole decelerator to decelerate antiprotons emerging from the CERN Antiproton Decelerator from MeV- to keV-scale energy, and collected five decelerated pulses in a multiring trap. Some 5 x 10(6) antiprotons were stacked in this way. Cooling of the trapped antiprotons by a simultaneously trapped electron plasma was studied nondestructively via shifts in plasma mode frequencies. We have also demonstrated the first step in extracting a 10-500 eV antiproton beam from the trap.

Journal Article↗
PubMed1975

Effects on breathing mechanics and gas exchange of different inspiratory gas flow patterns during anaesthesia.

Ten patients without known cardiac or respiratory disease were investigated with breathing mechanics and gas exchange studies during anaesthesia and artifical ventilation. The effects of three different inspiratory gas flow patterns, namely, accelerating, constant and decelerating flows were studied. A decelerating flow resulted in an increase of total compliance when compared to an accelerating or a constant flow. However, at the same time, there was an increase in physiological dead space and a decrease in alveolar ventilation with a decelerating flow compared to an accelerating flow. These results seem to indicate an improved gas distribution in the greater airways with a decelerating flow pattern, but when the total effects of gas exchange were judged, the greatest benefits were with an accelerating flow.

Adult↗
PubMed1997

Early amniotomy increases the frequency of fetal heart rate abnormalities. Amniotomy Study Group.

OBJECTIVE: To determine whether early amniotomy, when practised as an isolated intervention, increases the hourly rate of fetal heart rate record abnormalities. DESIGN: This is a secondary analysis of the results of a multicentre randomised trial of early versus late amniotomy in labour. SETTING: Secondary and tertiary level teaching hospitals. INTERVENTION: Early amniotomy versus an attempt to conserve the amniotic membranes. MAIN OUTCOME MEASURES: The hourly rates of early, mild variable, severe variable and late decelerations; caesarean section rates. RESULTS: Severe variable decelerations, when classified as categorical events (> or = 1/h to 2/h, > or = 2/h to < 4/h, > or = 4/h), were more frequent in the amniotomy group (chi2 for trend = 5.7, P = 0.017). The mean hourly rates of severe variable and late fetal heart rate decelerations were increased in the amniotomy group (severe variable: amniotomy group 1.4/h, control 0.7/h, P = 0.021; late: amniotomy group 3.3/h, control 2.3/h, P = 0.011). Although the overall rate of caesarean was similar in the two groups (OR 1.2; 95% CI 0.8-1.8), there was an increase in caesarean section for fetal distress (OR 2.3; 95% CI 1.1-4.5) associated with amniotomy. CONCLUSION: Our data suggest that early amniotomy increases the hourly rate of severe variable fetal heart rate decelerations without evidence of an adverse effect on neonatal outcome. In settings where the diagnosis of fetal compromise is based primarily on electronic monitoring, caesarean section for fetal distress may be increased by early amniotomy.

Adult↗