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PubMed1998

Routine helical computed tomographic evaluation of the mediastinum in high-risk blunt trauma patients.

BACKGROUND: The indications and method of evaluation of the mediastinum in blunt deceleration trauma are controversial and vary among centers. Most centers practice a policy of angiographic evaluation only in the presence of an abnormal mediastinum on chest radiography. Routine aortography in the absence of any mediastinal abnormality is not widely practiced. Helical computed tomographic (CT) scan has been successfully used in recent studies in the evaluation of the thoracic aorta. OBJECTIVE: To determine the role of routine helical CT scan evaluation of the mediastinum in patients involved in high-speed deceleration injuries, irrespective of chest radiographic findings. DESIGN: A prospective study over a 1-year period. Included in the study were patients with high-speed deceleration injuries who required CT evaluation of the head or abdomen. This group of patients underwent routine helical CT evaluation of the mediastinum irrespective of chest radiographic findings. SETTING: Large, urban, academic level I trauma center. RESULTS: A total of 112 trauma patients fulfilled the criteria for study inclusion. Overall, there were 9 patients (8.0%) with aortic rupture. Four (44.4%) of these patients had a normal mediastinum on the initial chest x-ray film and the diagnosis was made by CT scan. The CT scan was diagnostic in 8 of the aortic ruptures (intimal tear or pseudoaneurysm) and was suggestive of aortic injury but not diagnostic in 1 patient with brachiocephalic artery injury. In 42 patients (37.5%), there was a widened mediastinum: an aortic rupture was diagnosed in 5 of them (11.9%) and a spinal fracture in 9 (21.4%). One patient had both aortic rupture and spinal injury. CONCLUSIONS: The incidence of aortic injury in patients with high-speed deceleration injury is high. A significant proportion of patients with aortic injury have a normal mediastinum on the initial chest radiograph. There is a high incidence of spinal injuries in the presence of a widened mediastinum. We recommend that all trauma patients with high-risk deceleration injuries undergo routine helical CT evaluation of the mediastinum irrespective of chest radiographic findings.

Accidental Falls↗
PubMed1988

Predicting injury risk with "New Car Assessment Program" crashworthiness ratings.

The relationship between crashworthiness ratings produced by the National Highway Traffic Safety Administration's (NHTSA's) New Car Assessment Program (NCAP) and the risk of incapacitating injury or death for drivers who are involved in single-car, fixed-object, frontal collisions was examined. The results are based on 6,405 such crashes from the Motor Vehicle Traffic Accident file of the Texas Department of Highways and Public Transportation. The risk of injury was modeled using logistic regression taking into account the NCAP test results for each individual model of car and the intervening effects of car mass, age of the driver, restraint use, and crash severity. Three measures of anthropometric dummy response, Head Injury Criterion (HIC), Chest Deceleration (CD), and femur load were used to indicate vehicle crash test performance. The results show that there is a significant relationship between the results of the NCAP tests and the risk of serious injury or death in actual single-car frontal accidents. In terms of overall injury, chest deceleration was a better predictor than the Head Injury Criterion. For restrained drivers, crash severity, driver age, and chest deceleration were significant parameters for predicting risk of serious injury or death; the risk of injury decreased as chest deceleration decreased. The results were similar for unrestrained drivers although vehicle mass and femur load were also significant factors in the model. The risk of overall injury decreased as chest deceleration decreased but appeared to decrease as femur load increased.

Accident Prevention↗
PubMed2006

An experimental cadaveric study for a better understanding of blunt traumatic aortic rupture.

BACKGROUND: Blunt traumatic aortic rupture (BTAR) is a common catastrophic injury leading to death. Considerable uncertainty remains regarding the pathogenic cause. This study examines the comportment of the heart and the aorta during a frontal deceleration. METHODS: Accelerometers were placed in the right ventricle of the heart, the aorta, the sternum, and the spine of six trunks removed from human cadavers. Different vertical decelerations were applied to cadavers and the relative motion of these organs was studied (19 tests). RESULTS: The deceleration recorded in the isthmus of the aorta was always higher that the one recorded in the heart (p < 0.05). The difference of deceleration was 17% and increased with the speed's fall (extremes 5-25%). There was no significant difference of deceleration between the bony structures of the thorax. These results experimentally demonstrate for the first time that the fundamental mechanism of BTAR is sudden stretching of the isthmus of the aorta. CONCLUSION: Four mechanisms are suspected to explain the location of the rupture: two hemodynamic mechanism (sudden increase of intravascular pressure and the water-hammer effect), and two physical mechanisms (sudden stretching of the isthmus and the osseous pinch). A greater understanding of the mechanism of this injury could improve vehicle safety leading to a reduction in its incidence and severity. Future work in this area should include the creation of an inclusive, dynamic model of computer-based modeling systems. This study provides for the first time physical demonstration and quantification of the stretching of the isthmus, leading to a computerized model of BTAR.

Aorta↗
PubMed1998

Evaluation of left ventricular diastolic function from the pattern of left ventricular filling.

The pattern of left ventricular (LV) filling can be determined by Doppler echocardiography. Normally most LV filling occurs early in diastole, with some additional filling occurring during atrial systole, late in diastole. In the absence of mitral stenosis, three patterns of LV filling indicate progressively greater diastolic dysfunction: (1) Reduced early diastolic filling with a compensatory increase in importance of atrial filling, termed a pattern of "impaired relaxation;" (2) "pseudo-normalization" with most filling early in diastole but with rapid deceleration of mitral flow; and (3) "restricted filling" with almost all filling of the LV occurring very early in diastole in association with very rapid deceleration of mitral flow. A large, prolonged atrial regurgitant flow in the pulmonary veins also indicates impaired diastolic performance. The time for early filling deceleration is predominantly determined by LV stiffness: the shorter the deceleration time, the stiffer the LV. Patients with short deceleration time have a poor prognosis.

Blood Flow Velocity↗
PubMed1979

[Investigations for simplification of the clinical rotation test of irritability of the human vestibular organ (author's transl)].

Fifty ear-sound adolescents were rotated by constant acceleration and deceleration. These investigations yielded three results. 1. The nystagmus of acceleration and deceleration period permits a more exact statement about rotation irritability of peripheral vestibular organ than the per-rotatoric fading nystagmus during constant rotation. 2. The stop out of constant rotation causes only a fading nystagmus, the postrotatorius I. Consequently, deceleration should substitute the stop with regard to its greater exactness. 3. Statistical comparison shows that electronystagmograms of acceleration and deceleration correspond to electronystagmograms of right and left rotation. Therefore, the clinical rotation test is practicable with only one direction of rotation. In this case, deceleration has to be of the same strength and duration as the acceleration.

Adolescent↗
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↗
PubMed1985

Prophylactic intrapartum amnioinfusion in patients with preterm premature rupture of membranes.

Patients with preterm premature rupture of the membranes are at increased risk to develop intrapartum variable decelerations and fetal distress. Short-term saline solution amnioinfusion may be of benefit in the treatment of variable or prolonged decelerations once they appear. In an effort to assess the benefit of prophylactic amnioinfusion, patients with preterm premature rupture of the membranes were studied during a 1-year period in a prospective randomized manner. Patients receiving prophylactic amnioinfusion had significantly decreased incidence and severity of variable decelerations in the first stage of labor (p less than 0.005). In the second stage of labor, the incidence of severe (p less than 0.005) and total (p less than 0.001) decelerations was also decreased in the treatment group. The umbilical arterial pH at delivery was significantly lower (p less than 0.001) as was the umbilical venous pH (p less than 0.005) in the newborn infants of control patients compared with those of patients receiving amnioinfusion. This suggests that prophylactic intrapartum amnioinfusion is of significant benefit in reducing the incidence of variable decelerations and improving the metabolic state in newborn infants born to women with preterm premature rupture of the membranes.

Adult↗
PubMed1995

Rapid gain adaptation affects the dynamics of saccadic eye movements in humans.

The effect of rapid gain adaptation on the dynamics of visually guided saccades was investigated in six human subjects by using a search coil system. Saccadic adaptation was induced artificially by dislocating the target (by about 30% of the initial step) either forward (gain increase) or backward (gain decrease) during the primary saccade ("double-step paradigm"). Duration, peak velocity and peak acceleration and deceleration of a "standard 12 deg saccade" were computed from the data and were compared for the conditions of gain decrease, gain increase and the control without gain adaptation. The gain as well as the peak velocity and duration of the saccades showed an increased variability during the adaptation. In general, the abducting saccades had a higher peak acceleration than the adducting saccades, and all subjects showed an idiosyncratic pattern of the acceleration and deceleration. In the gain increase paradigm the subjects showed an increase in the duration and a decrease in the peak velocity. In the gain decrease paradigm there was a significant smaller ratio of peak acceleration/peak deceleration compared to the gain increase and the control condition. The findings demonstrate that rapid gain adaptation influences the dynamics of saccades in a specific way: peak saccadic velocity decreases and duration increases in the gain increase paradigm and peak acceleration/peak deceleration decreases in the gain decrease paradigm. Moreover, these results also suggest that the deceleration is neuronally controlled and not merely a result of mechanical constraints.

Adaptation, Physiological↗
PubMedDate not supplied

Phasic heart rate responses and cardiac cycle time in auditory choice reaction time.

This study investigated the cardiovascular-behavioral interaction under short and long stimulus interval conditions. In addition, the cardiovascular-behavioral interaction was studied as affected by cardiac cycle duration. Fourteen subjects performed a choice reaction time (RT) task employing a mixed speed-accuracy tradeoff design in which reactions were paced to coincide with a signal that occurs randomly at either 200 or 500 msec after the reaction stimulus. The preparatory interval between a warning stimulus and a lead-reaction stimulus complex was also varied (2 vs. 4.5 sec). Anticipatory deceleration occurred within the 4.5 sec interval but not in the 2 sec interval. The depth of anticipatory deceleration did not discriminate between fast and slow reactions; but an earlier shift from deceleration to acceleration was associated with fast reactions. The effect of stimulus timing relative to the R-wave of the electrocardiogram was also analysed. Meaningful stimuli tended to produce cardiac slowing as previously described in the literature. Early occurring stimuli prolong the cycle of their occurrence more than late occurring stimuli. The later prolong the subsequent cycle. Cardiac cycle time effects were absent for unattended stimuli. The results of anticipatory deceleration suggested that the depth of deceleration was regulated by time-uncertainty and speed-accuracy criterion.

Acoustic Stimulation↗
PubMed1993

Restrictive left ventricular filling pattern in dilated cardiomyopathy assessed by Doppler echocardiography: clinical, echocardiographic and hemodynamic correlations and prognostic implications. Heart Muscle Disease Study Group.

OBJECTIVES: This study was undertaken to evaluate the frequency of restrictive left ventricular filling pattern in dilated cardiomyopathy, as well as its clinical and hemodynamic correlations and prognostic implications. BACKGROUND: In dilated cardiomyopathy, as in other heart diseases, different left ventricular filling patterns were observed on Doppler echocardiography. Some patients showed a "restrictive filling pattern," similar to that associated with restrictive cardiomyopathy, characterized by predominant E waves and a shortened E deceleration time. METHODS: Pulsed Doppler transmitral curves were analyzed in 79 consecutive patients with dilated cardiomyopathy assigned to two study groups according to E deceleration time: group 1 (n = 36) had a restrictive left ventricular filling pattern (E deceleration time < 115 ms); group 2 (n = 43) had an E deceleration time > or = 115 ms. RESULTS: Patients in group 1 were significantly younger, in a higher New York Heart Association functional class, more frequently had a third heart sound and had a higher left ventricular filling pressure at catheterization. In addition, they showed more severe left and right ventricular dysfunction and dilation, a larger left atrium and more severe mitral regurgitation. A restrictive filling pattern was associated at Doppler study with a higher E wave velocity, lower A wave velocity and higher E/A ratio. During a follow-up interval of 22 +/- 14 months, all 14 patients who subsequently died or required heart transplantation showed a restrictive left ventricular filling pattern. At multivariate analysis, E deceleration time was the most powerful independent prognostic indicator of poor outcome or transplantation. CONCLUSIONS: Restrictive left ventricular filling pattern is frequent in dilated cardiomyopathy, is associated with more severe disease and is a powerful indicator of increased mortality risk and need for heart transplantation.

Adolescent↗
PubMed2006

Effects of circumferential or segmental pulmonary vein ablation for paroxysmal atrial fibrillation on cardiac autonomic function.

BACKGROUND: Circumferential and segmental pulmonary vein ablations are two established treatment strategies for ablation of atrial fibrillation. Both techniques require the application of radiofrequency current at anatomical sites that are close to autonomic ganglia. However, the effects of current pulmonary vein ablation techniques on cardiac autonomic function are unknown. OBJECTIVE: The purpose of this study was to analyze the short- and long-term effects of circumferential and segmental pulmonary vein ablation on cardiac autonomic function. METHODS: One hundred patients with highly symptomatic atrial fibrillation were randomly assigned to undergo either circumferential or segmental pulmonary vein ablation. Holter recordings were recorded at baseline and at regular intervals for up to 1 year after ablation. Autonomic function was assessed by deceleration capacity and acceleration capacity of heart rate as well as by standard measures of heart rate variability. RESULTS: In the circumferential pulmonary vein ablation group, deceleration capacity and acceleration capacity decreased highly significantly from 5.7 +/- 2.1 ms and -8.0 +/- 1.9 ms at baseline to 3.3 +/- 1.8 ms and -5.5 +/- 2.3 ms directly after ablation, respectively (P<.00001). Impairment of deceleration capacity and acceleration capacity was present up to 1 year after ablation. In the segmental pulmonary vein ablation group, deceleration capacity and acceleration capacity decreased from 5.8 +/- 2.0 ms and -7.8 +/- 1.6 ms at baseline to 3.4 +/- 1.2 ms and -6.0 +/- 2.4 ms directly after ablation (P<.00001), respectively. However, deceleration capacity and acceleration capacity returned to baseline values within 1 month. CONCLUSIONS: Circumferential and segmental pulmonary vein ablations induce an immediate decrease of autonomic function. However, while this decrease is only transient with segmental pulmonary vein ablation, it persists with circumferential pulmonary vein ablation for at least 1 year.

Aged↗
PubMed1998

Use of pulsed Doppler tissue imaging to assess regional left ventricular diastolic dysfunction in hypertrophic cardiomyopathy.

In this study, regional diastolic patterns and their relations with transmitral Doppler inflow were investigated in hypertrophic cardiomyopathy (HC) by pulsed Doppler tissue imaging (DTI). Doppler echocardiography and DTI of basal septum and lateral wall (apical 4-chamber view) were performed in 20 patients (15 men and 5 women) with HC and in 10 healthy subjects (7 men and 3 women). Diabetes, hypertension, coronary artery and valvular disease, mitral regurgitation, New York Heart Association functional classes III to IV, sinus tachycardia, atrial fibrillation, and inadequate echocardiograms were exclusion criteria. Peak velocity and time-velocity integral of early and late waves and their ratios, and deceleration and isovolumic relaxation times were determined by standard Doppler and by DTI at the septal and lateral wall levels. The 2 groups were comparable for age, heart rate, blood pressure, and ejection fraction. Transmitral peak velocity and time-velocity integral E/A ratios were reduced (both p <0.05) and deceleration and isovolumic relaxation times prolonged (both p <0.00001) in HC. Septal DTI showed lower peak velocity and time-velocity integral e/a ratios (p <0.00001 and p <0.001, respectively) and lengthened regional deceleration (p <0.01) and isovolumic (p <0.001) relaxation times. DTI of the lateral wall showed a prolongation of deceleration and isovolumic relaxation times (both p <0.01). By dividing HC according to transmitral E/A, 8 patients with E/A <1 had lower DTI septal e/a ratio (p <0.01) and prolonged septal deceleration and isovolumic relaxation times (both p <0.01) but no changes in DTI pattern of lateral wall than 12 patients with E/A > 1. In conclusion, DTI is useful and complementary to standard Doppler imaging to characterize diastolic properties in HC, reflecting a typical pattern of intramyocardial impaired relaxation at the level of hypertrophied septum and also providing information about the degree of this regional impairment. The lateral wall presents minor changes in diastolic times, which indicate how diastolic asynchrony is not confined to the hypertrophied segment in HC.

Adult↗
PubMed1999

Behavioral state affects heart rate response to low-intensity sound in human fetuses.

The cardiac orienting reflex is elicited by a low-intensity sound, it consists of a sustained heart rate (HR) deceleration, and it is a specific physiological correlate of cognitive processing. In this study we examined the relationship between behavioral state and the cardiac orienting reflex in 75 human fetuses between 36 and 40 weeks gestation. Each fetus was stimulated with a 30-s speech sound at an average intensity of 83 dB SPL in quiet sleep (QS) and active sleep (AS). The fetal cardiac electrical signal was captured transabdominally at a rate of 1024 Hz and fetal R-waves were extracted using adaptive signal processing. Fetal behavioral states were assigned based on HR pattern and the presence or absence of eye and general body movements. We found that a significant HR deceleration occurred, in both QS and AS, following stimulus onset. However, HR decelerations occurred more often in QS than AS; and for fetuses exhibiting a HR deceleration, the magnitude of the deceleration was greater in AS compared to QS. In addition, in AS female fetuses exhibited a larger, more sustained HR deceleratory response than male fetuses, but the seconds x gender interaction in QS was not significant. Based on these results, we concluded that behavioral state is an important determinant of the HR deceleratory response in human fetuses.

Acoustic Stimulation↗
PubMedDate not supplied

Mechanism of physiologic and pathologic S3 gallop sounds.

Although the S3 gallop sound has long been used clinically as an indicator of left ventricular systolic dysfunction, the mechanism responsible for its production remains controversial. The same sound is often found in young healthy individuals, and whether a similar mechanism is responsible is also unknown. The relationship of the S3 gallop sound to the dynamics of left ventricular filling was compared in 18 healthy young triathletes and 15 older subjects with cardiac disease. Twenty healthy normal subjects without an S3 were included as controls. Phonocardiographic, two-dimensional echocardiographic, and Doppler echocardiographic analysis of left ventricular inflow were evaluated. The S3 in both groups always occurred close to peak early filling velocity (E), during early flow deceleration. Mean E deceleration rate was higher in the subjects with S3 (726 +/- 153 cm/sec2 in the triathletes and 819 +/- 274 cm/sec2 in those with cardiac disease) than in control subjects (563 +/- 131 cm/sec2, p less than 0.001 in both cases). Ten triathletes underwent examination both before and immediately after 30 degrees head-up tilt. E deceleration rate dropped significantly with head-up tilt (720 +/- 137 vs 590 +/- 174 cm/sec2, p less than 0.01), while concurrently the S3 disappeared or was diminished in amplitude. Similar changes were seen in subjects with cardiac disease. We conclude that both the "pathologic" and "physiologic" S3 are related to abnormally rapid deceleration of early diastolic left ventricular inflow. Although the presence of the S3 is not dependent on the state of left ventricular systolic function, diastolic filling is characterized by a predominance of early inflow with a rapid flow deceleration rate.

Adult↗
PubMed2002

Reproducibility of the heart rate response to low-strain Valsalva manoeuvre in healthy subjects.

To elucidate whether the intrastrain cardio-acceleration and cardio-deceleration responses to low-strain Valsalva manoeuvre at expiratory pressures 10 and 20 mmHg (VM10,VM20) are reproducible, a beat-to-beat heart rate study was undertaken in 46 subjects (40 male undergraduates aged 19-25 years and six laboratory workers (four females and two males aged 28-55 years). The intensity of the heart rate response (HRR) was assessed by a ratio of the mean value of the pre-strain heart rate (Valsalva means' ratio VMR). In each subject the HRR to VM10 and VM20 was measured by repeating each manoeuvre three times. Reproducibility was evaluated on a short-term (1 h), medium-term (1 and 6 months), and long-term (6 and 11 years) basis. With the individual differences the initial short-term reproducibility study revealed either an cardio-acceleration or cardio-deceleration response to VM10 and VM20, which persisted well in the repeated tests. On the ground of this result three individual modes of HRRs to VM10 and VM20 were distinguished: (i) Mode A, a deceleration response appeared both to VM10 and VM20; (ii) Mode B, a deceleration response appeared to VM10 and an acceleration response to VM20; (iii) Mode C, an acceleration response appeared both to VM10 and VM 20. All of these modes, as well as the separate acceleration and deceleration responses, were well reproducible at any cited time points. We suggest that the individual modes of HRR are induced by different states of autonomic cardiovascular reactivity: Mode A probably expresses a parasympathotonic (vagotonic), Mode C--a sympathotonic, and Mode B--an intermediate autonomic state. Thus, the individual modes of HRR to VM10 and to VM20 could be used as a method of non-invasive determination of cardiovascular autonomic reactivity.

Adult↗
PubMed2005

Association of nonreassuring fetal heart rate patterns and subsequent cerebral palsy in pregnancies with intrauterine bacterial infection.

We evaluated an association of nonreassuring fetal heart rate (FHR) patterns and subsequent cerebral palsy (CP) in pregnancies with intrauterine bacterial infection. Among 10,030 infants born during 1995 to 2000, 139 were complicated with acute intrauterine bacterial infection in labor. The FHR patterns 2 hours immediately before delivery were interpreted according to the guidelines of the National Institute of Child Health and Human Development. The correlations between the FHR patterns and umbilical blood gases, as well as FHR patterns and CP were studied. Statistics included unpaired t test, contingency table with chi (2) and Fisher test, and one-way analysis of variance with Bonferroni/Dunn test. Fifteen infants (11%) developed CP at 2 years or older. Nonreassuring FHR patterns including recurrent late deceleration, severe variable deceleration, and prolonged deceleration occurred in 24% of pregnancies with intrauterine infection. Incidence of CP was not different according to the FHR deceleration patterns or umbilical pH values. Multiple logistic regression analysis revealed that fetal tachycardia (OR, 11; 95% CI, 1.8 to 67) and lower gestational age (< 34 weeks; OR, 9.4; 95% CI, 0.96 to 93) was associated with CP in intrauterine infection. Nonreassuring FHR patterns were increased in intrauterine infection. CP occurred more frequently and was associated with tachycardia and lower gestational age, but not with FHR deceleration patterns or acidemia, suggesting different pathophysiology from acute hypoxia-ischemia.

Cerebral Palsy↗
PubMed1995

[Doppler echocardiographic analysis of diastolic function in dilatative cardiomyopathy for the evaluation of its progression and prognosis].

The relationship between left-ventricular diastolic function and the course of the disease was investigated in a prospective study of 61 patients (44 men, 17 women; median age 51 [26-74] years) with dilated cardiomyopathy. The diastolic function was measured by recording the transmitral Doppler flow profile. During a follow-up period of 33 +/- 23 months, 15 patients died (twelve of progressive heart failure, three suddenly without previous heart failure). Cardiac transplantation was performed in four patients. The overall 1-year mortality rate was 14%. A "restrictive" Doppler echocardiographic filling pattern with a steep early-diastolic maximum and a small atrial filling component predominated in the patients who died from progressive heart failure or had a cardiac transplantation because of it. The deceleration of the early diastolic velocity maximum was clearly shorter than in the survivors (111 +/- 32 ms vs 194 +/- 62 ms; P < 0.001). In a Cox proportional hazard model the deceleration time was the best prognosticator, followed by the end diastolic left-ventricular diameter (LVD). The group of patients with a short deceleration time (< or = 140 ms) had a significantly higher 1-year mortality rate (28% [confidence interval 9-47%]) than those in whom it was longer (3% [0-11%]; P < 0.0001). Taking into account LVD it proved possible to identify a prognostically especially unfavourable group with a 1-year mortality rate of 53% (26-80%), characterized by a LVD > 70 mm and a deceleration time < or = 140 ms. Repeated echocardiography in 26 survivors and nine patients who died later or had been operated on showed that the deceleration time did not change significantly in the course of the disease. On the other hand, the systolic function, as measured by the echocardiographically determined shortening fraction, improved in the survivors (from 0.18 +/- 0.07 to 0.22 +/- 0.08; P < 0.05), but not in those who later on died.

Adult↗
PubMed2003

Intrapartum fetal heart rate patterns in the prediction of neonatal acidemia.

OBJECTIVE: This study was undertaken to correlate changes in the intrapartum electronic fetal heart rate patterns with the development of significant neonatal acidemia. STUDY DESIGN: We identified 488 fetuses at a gestational age of >37 weeks' gestation who had continuous electronic fetal monitoring during labor for the last 2 hours and umbilical artery cord gas analysis performed at delivery. One investigator blinded to the cord gas outcome reviewed all 488 tracings using the National Institute of Child Health and Human Development guidelines for fetal heart rate monitoring. All fetal heart rate tracings with bradycardia were removed from further analysis. The patients were placed in six groups, depending on the absence or presence of normal variability (amplitude >5 beats) during the last hour of monitoring combined with the absence of decelerations or the presence of variable or late decelerations. The relationship between changes in variability and the outcome variables of pH and base deficit in the six groups was assessed with analysis of variance and chi(2) test. Significance was set at the P <.05 level. RESULTS: Patients with normal variability and accelerations, even in the presence of late decelerations or variable decelerations, maintained an umbilical artery pH 7.0 or greater in more than 97% of cases. In the presence of minimal/absent variability (amplitude <5) for at least an hour, the incidence of significant acidemia (pH <7.0) ranged from (12%-31%). CONCLUSION: The most significant intrapartum fetal heart rate parameter to predict the development of significant acidemia is the presence of minimal/absent variability for at least 1 hour as a solitary abnormal finding or in conjunction with late decelerations in the absence of accelerations. Urgent delivery should be considered in these cases after appropriate ancillary testing.

Acids↗