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PubMed1984

Clinical features of the reactive positive contraction stress test.

During a five-year period, 2815 patients undergoing 5685 fetal heart rate (FHR) tests produced 147 positive contraction stress tests. Baseline FHR patterns were considered reactive if three or more accelerations occurred during 30 minutes of the contraction stress test and nonreactive if fewer or no accelerations were noted. There were 75 reactive positive contraction stress tests and 72 nonreactive positive contraction stress tests. Both groups were promptly delivered, generally (91%) within 24 hours of the last test. Fetuses producing reactive positive patterns tended to be more mature, larger, and most frequently tested for postmaturity. Fetuses with nonreactive positive patterns had significantly higher rates of perinatal mortality and morbidity, growth retardation, and cesarean deliveries; they were frequently carried by hypertensive mothers. Each group was analyzed according to deceleration: contraction ratio, and deceleration: contraction ratio deciles from 30 to 100% were examined. Perinatal complications increased progressively with higher deceleration: contraction ratios, irrespective of baseline reactivity; however, nonreactive fetuses in any deceleration: contraction ratio decile had more frequent perinatal compromise than their reactive counterparts. The lack of specificity (26 poor outcomes in 75 cases) associated with the reactive positive contraction stress tests encourages more frequent attempts at vaginal delivery; in this group, 64 of 71 patients had successful vaginal deliveries. Furthermore, the high incidence of good fetal outcome in the reactive positive group suggests that the urgency of delivery in such circumstances be reassessed and that other fetal-maternal indicators be considered in delivery decisions.

Apgar Score↗
PubMed1982

Nonstress test prediction of fetal status.

Eighty-six patients were selected from the high-risk group delivered at Lincoln Hospital in New York City, constituting 22% of the total of 3,500 patients delivered. All of them underwent a nonstress test (NST) and oxytocin challenge test (OCT) antepartally and were also monitored during labor. Sixty-six of them had reactive nonstress patterns, all associated with a negative OCT. Three of them who had reduced variability developed late decelerations in labor; only one had a low Apgar score. Nineteen patients had absence of unequivocal accelerations, five associated with a negative OCT. Of these, only one developed late decelerations in labor. Of 14 others with nonreactive or combined positive OCT patterns, 9 developed late decelerations in labor. Two of them who also had reduced variability developed severe late decelerations in early labor, were delivered by cesarean section and had severe perinatal asphyxia. One case of baseline bradycardia was observed, and the patient did well. When reactive, NST appears to be as reliable as a negative OCT as an indicator of antepartum fetal well-being. Labor may be a life-threatening stress for fetuses displaying nonreactive positive OCT patterns with diminished variability.

Female↗
PubMed1982

The beneficial effect of vacuum extraction of the fetus.

The vacuum extractor (VE) was applied electively after approximately 25 min of expulsion in 25 normal primiparae. Twenty-five identical parturients with spontaneous deliveries served as controls. The fetal scalp pH was measured at the beginning of the 2nd stage, and again in the cord blood of all newborns. Cardiac monitoring by scalp electrode was done for all fetuses throughout labor. The mean pH of the first blood sample was almost identical in the two groups, while the mean decrease in pH in the VE group was 0.077, against a mean change of 0.106 in the controls (p less than 0.05). In the FHR graph the total area of deceleration, and separately in the controls (p less than 0.05). In the FHR graph the total area of deceleration, and separately the up to 30 beats/min (area A) and of more than 30 beats/min (area B) were calculated. The mean total area of deceleration in the VE group was 14.76 cm2vis-à-vis 17.56 cm2 in the controls. Areas A and B were also smaller in the study group, but these differences were not statistically significant. The mean total deceleration time in the VE fetuses was 22.8 min, and 37.75 min in the controls (p less than 0.001). It is concluded that the application of the VE during the second stage lessens fetal depression, when compared with spontaneous delivery.

Extraction, Obstetrical↗
PubMed1980

Face presentation at term.

A retrospective study was conducted of 50,300 consecutive deliveries between July of 1973 and January of 1978. There were 40 instances of face presentation with gestational age greater than 36 weeks and fetal weight greater than 2500 g for an incidence of 1 per 1250 deliveries. Cesarean section was performed in 50% of cases. Spontaneous vaginal delivery occurred with mentum anterior presentation 88% of the time, with mentum transverse presentation 45% of the time, and with mentum posterior presentation 25% of the time. Fetal heart rate (FHR) monitoring was available for review in 29 of the 38 (76%) live births. Internal techniques were used in 79% and external techniques in 21% of the cases. The FHR patterns were classified according to the predominant pattern seen in the first stage of labor. In 59% (17 of 29), variable decelerations were noted, and severe variable decelerations were present in 29% (8 of 29). Late decelerations were noted in 24% (7 of 29) of cases. Only 4 patients completed labor without variable or late decelerations. There were 38 live births and 2 stillbirths. Both of the stillborns were noted to have tight nuchal cords which were believed to be the cause of death. One death occurred intrapartum. Of the 38 live births, there were 14 (37%) with 1-minute Apgar scores of 6 or less and 5 (13%) with 5-minute Apgar scores less than 7. Four of the 5 low 5-minute Apgar scores occurred in babies with mentum posterior position. Of the 23 patients monitored by internal electrodes, no serious trauma was noted as a result of the electrode placement.

Adult↗
PubMed1980

FHR variability and other heart rate observations during second stage labor.

Seventy-four fetal heart rate (FHR) records that were continued to vaginal delivery were selected for study from more than 2000 intrapartum FHR tracings. Thirty-six of the births were associated with neonatal depression and Apgar scores of 3 or less and/or 6 or less at 1 and 5 minutes, respectively; 38 patients exhibited normal Apgar scores (7 and 10 at 1 and 5 minutes, respectively). Twenty minutes of heart rate activity immediately prior to birth was the basis of analysis. All categories of loss of short-term beat-to-beat variability (BBV), both baseline and with decelerations, were observed more frequently in the group with low Apgar scores (P less than .001). In assessing variability, duration of observed loss of BBV appears to be an extremely critical factor. If BBV was lost 50% or less of observation time, a wide range of Apgar scores was observed. When more than 50% of the record showed loss of BBV, the number of depressed neonates was relatively high. Bradycardia (heart rate of less than 120 beats per minute) was present frequently in the records of the normal group. The number of variable decelerations and the amount of uterine activity were relatively high during second stage labor; a similar frequency was noted in both groups. Decelerations were nearly uniformly associated with uterine contractions in both groups, and accelerations were also noted in both groups. Uniform decelerations (late) were also present in both groups, with a greater frequency in the group with lower Apgar scores, but there were no distinguishing characteristics noted.

Apgar Score↗
PubMed1980

[25 cases of traumatic rupture of the thoracic aorta: current diagnostic elements].

Traumatic rupture of the descending thoracic aorta is lethal within 3 weeks in 95% of patients who do not undergo operation. In this series of 25 patients who were operated on, 84% have survived for 6 years and there have been no cases of paraplegia. The mechanism of injury is most important in the investigation of patients with traumatic injuries and must be sought either from the patient or from witnesses. A history of rapid deceleration (more than 60 km/h) following a highway collision was present in all our cases. Failure to wear seat-belts resulted in 70% of patients being ejected from a vehicle. A side-on collision resulting in lateral deceleration caused trauma to the intrathoracic aorta in 45% of cases. Vertical deceleration resulted from falls from great heights (bridge, overpass) in 25% of cases. Clinical signs of diagnostic importance were: arterial hypertension (60%), systolic murmur (35%) and the pseudocoarctation syndrome (25%). Pertinent signs on chest roentgenograms were present in 95% of cases and included widening of the mediastinum and blunting of the aortic knob. The authors conclude thoracic aortography should be carried out in trauma patients when two or more of the following are present: (a) history of rapid deceleration, ejection from a vehicle or lateral collision, (b) hypertension and (c) blunting or modification of the aortic knob. The presence of a pseudocoarctation syndrome is an absolute indication for aortography.

Accidents, Traffic↗
PubMed1995

Interrelationship of left ventricular mass, systolic function and diastolic filling in normotensive morbidly obese patients.

OBJECTIVE: To determine the interrelationship of left ventricular (LV) mass, systolic function and diastolic relaxation in morbidly obese subjects. METHOD: We obtained echocardiograms (M-mode, two dimension) and cardiac Doppler studies (pulse wave, continuous wave colour flow) on 50 subjects whose actual body weight was > or = twice ideal body weight. LV mass/height index was calculated from echocardiographic data (Penn Convention). LV systolic function was assessed by calculating LV fractional shortening. LV diastolic filling was assessed by measuring the transmitral Doppler E/A ratio and the transmitral E wave deceleration time. RESULTS: There were significant positive correlations between LV mass/height index and the LV internal dimensions in diastole, systolic blood pressure, LV end-systolic wall wall stress and the transmitral E wave deceleration time. There were significant negative correlations between LV mass/height index and both LV fractional shortening and the transmitral Doppler E/A ratio. There were significant negative correlations between LV fractional shortening and the LV internal dimension in diastole, systolic blood pressure LV end-systolic wall stress and the transmitral E wave deceleration time. There was a significant positive correlation between LV fractional shortening and the transmitral Doppler E/A ratio. There were significant positive correlations between the transmitral E wave deceleration time and LV internal dimension in diastole, systolic blood pressure and LV end-systolic wall stress. There were significant negative correlations between the transmitral Doppler E/A ratio and the aforementioned variables. CONCLUSIONS: Unfavourable alterations in LV loading conditions contribute to the development of LV hypertrophy and impairment systolic dysfunction in morbidly obese subjects. Increasing LV mass and altered loading conditions may synergistically contribute to impairment of LV diastolic filling in such individuals.

Adult↗
PubMedDate not supplied

Fetal heart rate patterns and the timing of fetal injury.

We studied the nonstress test (NST) results and other perinatal features of 44 children with cerebral palsy, who had fetal heart rate (FHR) patterns during labor suggesting preexisting injury. This was a retrospective, descriptive study. All fetuses persistently showed absent variability and small, variable decelerations, with overshoot from the onset of monitoring during labor. During the initial NST, 84.1% of fetuses revealed normal reactive NST patterns (three with decelerations). Six fetuses (15.9%) had nonreactive NST results (three with decelerations). The conversion of the reactive NST to a pattern of persistently absent variability often occurred during advanced pregnancy (average estimated gestational age 40 weeks), in association with decreased amniotic fluid (AF) volume (70.5%) and maternal complaints of decreased fetal movement (52.4%). FHR decelerations consistent with acute fetal distress were uncommon during early labor but occurred in about half of cases in advanced labor. All but one neonate had low Apgar scores at birth, but acidosis occurred in about one third of infants. Seizures developed in about half the infants, usually in the first day. Follow-up studies revealed a high incidence of mental retardation, microcephaly, and seizure activity in addition to cerebral palsy, regardless of the presence of perinatal acidosis. The results of this retrospective study of a limited population base suggest that fetal neurologic injury preceding labor may develop late in pregnancy, and that decreased AF volume appears to be a significant risk factor. FHR patterns may provide clues to the presence and timing of fetal neurologic injury.

Cerebral Palsy↗
PubMed1994

Prophylactic amnioinfusion for oligohydramnios: a reevaluation.

OBJECTIVE: To compare the effects of prophylactic amnioinfusion to standard care plus indicated therapeutic amnioinfusion (for variable decelerations) in term patients with oligohydramnios. METHODS: One hundred sixteen term gestations with oligohydramnios (amniotic fluid index less than 5.0 cm) were randomly assigned to receive prophylactic saline amnioinfusion (600-mL bolus followed by 3 mL/minute) or standard obstetric care (control). Control patients who subsequently developed moderate or severe variable decelerations received therapeutic amnioinfusion. RESULTS: There was no significant difference in overall cesarean delivery (21 versus 17%; P = .68), cesarean delivery for fetal distress (7 versus 10%; P = .83), or umbilical gas values between the prophylactic amnioinfusion group (N = 56) and control group (N = 60), respectively. The rate of intrapartum fever was significantly increased among the prophylactic amnioinfusion patients (23 versus 7%; P = .02), although the duration of intrauterine monitoring (8.8 versus 6.5 hours; P = .06) and time from ruptured membranes to delivery (12.3 versus 14.3 hours; P = .51) were not different. Only 22% of the controls developed moderate or severe variable decelerations in the first stage of labor and received therapeutic amnioinfusion. Thus, in approximately four of five term patients with oligohydramnios, neither prophylactic nor therapeutic amnioinfusion would be indicated. CONCLUSIONS: Compared to indicated amnioinfusion, prophylactic amnioinfusion did not improve perinatal outcome. Amnioinfusion should be reserved for term laboring patients with variable fetal heart rate decelerations, rather than all patients with oligohydramnios.

Adult↗
PubMed1996

Characteristics of fetal heart rate changes during the expulsive stage of bovine parturition in relation to fetal outcome.

OBJECTIVE: To characterize fetal heart rate (FHR) patterns of nonacidotic (N-AC) and acidotic (AC) calves during the expulsive stage of parturition. ANIMALS: 32 calves born to heifers, either unassisted or by moderate traction. PROCEDURE: Cardiotocograms (CTG) evaluated qualitatively (visual) and quantitatively by a moving window technique (width 10, shift 5 minutes) for baseline FHR, variability, and periodic alterations (accelerations and decelerations). RESULTS: Significant differences were apparent between increase in baseline FHR of N-AC and AC calves; change in FHR (delta-FHR), taking into account individual FHR, is a more discriminating parameter. The predominant reaction to uterine contraction is a decrease in FHR; variable decelerations were the most common type in both groups, and late decelerations were seen only in AC calves. Additional characteristics of variable decelerations were more frequently seen in AC calves. CONCLUSIONS: CTG parameters during expulsion can discriminate between AC and N-AC calves, but specific characteristics are not exclusively restricted to AC or N-AC calves. CLINICAL RELEVANCE: CTG recordings during bovine parturition in cattle provide information on the fetal condition and can be used in the future to study the effects of medication and manipulations to the fetus.

Acidosis↗
PubMed1996

[Left ventricular structure and (systolic and diastolic) function in hypertensive patients without atherosclerotic coronaropathy].

INTRODUCTION AND OBJECTIVES: Electrocardiographic (ECG) ST-T segment abnormalities in hypertensive patients are traditionally associated with hypertrophy and/or ischaemia and a higher cardiovascular risk. Hypertensive patients with typical or non-typical chest discomfort and a normal coronarographic study underwent an echocardiographic and Doppler study in order to assess left ventricular structure and (systolic and diastolic) function. MATERIAL AND METHODS: Hypertensive patients with ST-T changes were classified as follows: Control group (CG) was made up of 12 hypertensive patients (6 women, 6 men, mean age 59.6 +/- 7.4 years) with normal ECG; Group A (GA), 10 patients (6 women, 4 men, mean age 63.1 +/- 6.8 years) with ECG image of strain; Group B (GB) (9 women and 8 men, mean age 61.3 +/- 10.1 years) with other ST-T alterations. We assessed by echocardiographic and transmitral flow Doppler study left ventricular structure and (systolic and diastolic) function. RESULTS: Interventricular septum thickness, left ventricular posterior wall thickness, left ventricular mass and mass index were significantly higher in the GA and GB than in the CG, without differences between GA and GB groups. No differences in left ventricular systolic function parameters were observed between the groups. In comparison with the CG, the GA and GB showed significant differences in E wave deceleration velocity and deceleration time, A wave deceleration time and isovolumetric relaxation time. Between GA and GB differences were observed in A wave deceleration time and isovolumetric relaxation time. CONCLUSIONS: In hypertensive patients without atherosclerotic coronaropathy, ST-T changes identify a group with greater left ventricular mass and worse left ventricular diastolic function. The patients with a ST-T strain pattern showed the impaired diastolic function.

Aged↗
PubMed1976

Electronic fetal monitoring during labor.

Intrapartum electronic fetal monitoring tracings from 620 women monitored internally over 60 minutes were analyzed. Fetal heart rate patterns were statistically analyzed against four variables of labor: 1) the presence of meconium; 2) fetal acidosis; 3) 1-minute Apgar score; and 4) clinical correlates considered as etiologic factors in FHR decelerations. No significant etiologic correlation was found between these clinical correlates and FHR deceleration patterns. Statistically significant correlations were established between poor neonatal outcome and fetal acidosis (P less than 0.01) and the presence of meconium (P less than 0.05). No correlation was found between FHR patterns and fetal acidosis. Variable deceleration showed no significant relation to low Apgar score (less than or equal to 6). Late deceleration showed a significant correlation with depressed infants. FHR patterns are best used as an alarm system of fetal difficulty than as an absolute measure of fetal distress.

Acidosis↗
PubMed1998

[Echocardiographic evaluation of left ventricular diastolic function in patients with dilated cardiomyopathy: correlation among doppler, hemodynamic and clinical findings].

In order to evaluate the prognostic implications of either transmitral filling parameters and pulmonary artery capillary pressure, 35 patients (23 men, age 63 +/- 13 years, +/- SD) with idiopathic (n = 19) or ischemic (n = 16) dilated cardiomyopathy (NYHA class II-IV) underwent Doppler echocardiography and right cardiac catheterization. None of them had atrial fibrillation, severe mitralic valvular disease, a advanced atrial-ventricular heart block, or was pace-maker implanted. Two groups of patients were identified on the basis of status symptoms: Group 1 (n = 12; NYHA class IIa-IIb), Group 2 (n = 23; NYHA class III-IV). As to diastolic parameters, the 2 groups significantly differed in peak E velocity (p < 0.001), deceleration time (p < 0.001), E/A ratio (p = 0.0004), E wave duration (p < 0.05) and isovolumetric time relaxation (p < 0.05). A restrictive-type transmitralic filling (high mitral E wave velocity, low mitral A wave velocity, low deceleration time), was found in 4 (33%) patients of Group 1 and in 20 (86%) patients of Group 2. Group 2 patients had significantly higher pulmonary artery capillary pressure (p < 0.001) than Group 1 patients. During the follow-up (18 +/- 6 months; from 8 to 22 months), 6 patients experienced cardiac death (4 died of sudden death and 2 for congestive heart failure), 1 patient underwent cardiac transplantation, and 6 patients had deterioration of status symptoms. All of the 7 major cardiac events and 3 out of 6 deteriorations of status symptoms occurred in patients of Group 2. With a Cox analysis, deceleration time (beta-0.096, SE = 0.03, p < 0.005), pulmonary artery capillary pressure (beta-0.027, SE = 0.01, p < 0.001), and left ventricular ejection fraction (beta-0.098, SE = 0.32, p < 0.006) were predictive of major cardiac events. The univariate prognostic predictors were found to be: E/A ratio (r = 0.72, p < 0.05), deceleration time (r = -0.90, p < 0.05), and isovolumetric time relaxation (r = -0.74, p < 0.05). Assessment of transmitral filling by Doppler echocardiography is a simple, reproducible and noninvasive method, providing effective functional and prognostic information on patients with dilated cardiomyopathy. The correlation found between several transmitral filling parameters and pulmonary artery capillary pressure provides an accurate noninvasive estimation of hemodynamics in these patients.

Aged↗
PubMed1996

The mechanical properties of the heel pad in elderly adults.

The shock absorbing characteristics of the heel pad in vivo were examined in two groups of active elderly individuals whose ages ranged between 60 and 67 years (n = 10) and between 71 and 86 years (n = 10). For comparative purposes, young adults (n = 10) aged between 17 and 30 years were also examined. A free-fall impact testing device which consisted of an instrumented shaft (mass 5 kg), accelerometer and position detection transducer was used to obtain deceleration and deformation of the heel during impact. The data were obtained from impact velocities of 0.57 m.s-1 (slow) and 0.94 m.s-1 (fast). Peak values of the deceleration and deformation, as well as the time to these peaks from onset of impact, and energy absorption were evaluated. At the slow impact velocity, no age effect was found for the parameters examined except for the energy absorption. At the fast impact velocity, there was higher peak deceleration and smaller deformation for the elderly than for the younger adults. The energy absorbed was less for the elderly than for the younger adults. It was concluded that the capacity for shock absorbency of the heel pad declines with age.

Adolescent↗
PubMed1981

Optical information for detecting loss in one's own forward speed.

An experiment was conducted to determine whether accuracy and efficiency of detecting loss in one's own forward speed are constant when optical information is invariant over a wide range of environmental variables. Deceleration rate, initial forward velocity, and altitude were varied so as to isolate initial optical flow rate, optical flow deceleration, and optical flow damping invariants specified in observer-relevant metrics. The candidate resulting in the most consistent effect on performance was global damping, which specifies a contrast of flow deceleration with initial flow rate. The finding is a first step toward validating a procedure for identifying functional invariants by assessing the usefulness of mathematically specified optical information for the perception of egomotion. The research represents both a methodological development and empirical support for the broader program of ecological functionalism.

Acceleration↗
PubMed1997

The acceleration-velocity relationship: identification of normal and spastic upper extremity movement.

This study defines and evaluates a non-invasive technique that will identify a spasm as an uncommanded movement (U) from a normally commanded movement (C). Upper arm function during a tracking task is recognized as non-linear and characterized by a phase plane with acceleration (second derivative of stick position) plotted on the ordinate and velocity (first derivative of stick position) plotted on the abscissa. An acceleration time constant (tau A) is defined as (VA/AM) where AM is the maximal acceleration and VA is the velocity at AM. A deceleration time constant (tau D) is also defined as (VD/DM), where DM is the maximal deceleration and VD is the velocity at DM. Ten spastic subjects (S) were categorized into three groups of mildly spastic (M), intermediately spastic (I), and highly spastic (H) which were compared to five normal subjects (N). The results indicate that for C and U, both VA and AM are significantly lower for S at all three levels as compared to N. tau A is significantly higher for M and I as compared to N. Both VD and tau D are significantly higher for S at all three levels when compared to N. DM is significantly lower for S at all three levels of S when compared to N. Finally, AM and tau A significantly differentiate C vs U for M. VA and tau D significantly differentiate for I. VA, AM as well as DM, tau D significantly differentiate for H. The physical significance of these results is discussed with respect to the time course and magnitude of net muscle moment (M), and the reversal of the agonist-antagonist relationship during the acceleration and deceleration phases. Finally, a spasm identification algorithm is proposed.

Acceleration↗
PubMed1995

Visual control of braking: a test of the tau hypothesis.

Deceleration during braking could be controlled by (a) using the time derivative of the relative rate of optical expansion, relative to a -0.5 margin value of tau-dot (D.N. Lee, 1976) or (b) computing the required deceleration from spatial variables (i.e., perceived distance, velocity, or object size). Participants viewed closed-loop displays of approach to an object and regulated their deceleration with a brake. The object appeared on a checkerboard ground surface (providing velocity, distance, and size information) or with no background (providing only optical expansion). Mean tau-dot during braking was -0.51, and estimates of the critical value of tau-dot based on brake adjustments were -0.44 and -0.52, close to the expected value. There were no overall effects of the ground surface or object size. The results are consistent with a tau-dot strategy, where the direction and magnitude of brake adjustments are regulated using tau-dot.

Acceleration↗
PubMed1976

The visual perception of accelerated motion.

The present research is an investigation of how changes in the rate of motion are percieved. Five separate experiments were performed with the use of filmed stimulus material and a variety of response measures, including both categorical judgments and reporduction techniques. It was found that (a) the smaller the ratio of terminal to initial velocity, the less frequent the judgments of acceleration or deceleration, (b) deceleration was significantly easier to perceive than acceleration, (c) the perception of acceleration was facilitated when the velocity of a lead-in segment was the same as the velocity at onset of motion, (d) a short tunnel centered in the motion path facilitated the perception of acceleration and deceleration, and (e) instantaneous changes in velocity were much more easily perceived than gradual changes. A one-event model for the perception of motion change in which there is a continuous interplay between earlier, later, and interpolated motion segments is favored over a two-event model in which earlier and later segments of velocity are compared.

Acceleration↗