[Subcutaneous teicoplanin for children with infectious endocarditis]. / Teicoplanine par voie sous-cutanée chez l'enfant présentant une endocardite infectieuse.

BACKGROUND: Infectious endocarditis in children requires prolonged antibiotic therapy. In adults, antibiotics administrated subcutaneously such as teicoplanin are an alternative to intravenous treatment. CASE REPORT: We report the use of subcutaneous teicoplanin, after an initial antibiotic treatment administrated intravenously, for 2 children treated for infectious endocarditis following an initial cardiac surgery. Serum concentrations of teicoplanin were within the target range after the adaptation in the teicoplanin subcutaneous dosages. The treatment was effective for both cases. No specific side effects related to the treatment were reported. DISCUSSION: Subcutaneous administration could be used for prolonged antibiotic therapy for the treatment of infectious endocarditis in children, after an initial intravenous treatment. Variability of the bioavailability of antibiotics administrated subcutaneously requires regular testing. Prospective, randomized trials comparing intravenous and subcutaneous administration of teicoplanin should be conducted to assess the efficacy and safety of this treatment.

Phase-based level set segmentation of ultrasound images.

Ultrasonic image segmentation is a difficult problem due to speckle noise, low contrast, and local changes of intensity. Intensity-based methods do not perform particularly well on ultrasound images. However, it has been previously shown that these images respond well to local phase-based methods which are theoretically intensity invariant. Here, we use level set propagation to capture the left ventricle boundaries. The proposed approach uses a new speed term based on local phase and local orientation derived from the monogenic signal, which makes the algorithm robust to attenuation artifact. Furthermore, we use Cauchy kernels, as a better alternative to the commonly used log-Gabor, as pair of quadrature filters for the feature extraction. Results on synthetic and natural data show that the proposed method can robustly handle noise, and captures well the low contrast boundaries.

[Congenital transient leukemia: a case report]. / Un cas de leucémie congénitale transitoire.

UNLABELLED: Neonates with Down's syndrome have an increased risk for congenital leukaemia, particularly acute megakaryoblastic leukaemia (FAB, M7) which most often resolves spontaneously and is called transient leukaemia. It can be observed in non-constitutional trisomy 21 infants then presenting trisomy 21 on blasts cells. OBSERVATION: We report a transient leukaemia with an isolated pericardial effusion in a phenotypically normal neonate. Trisomy 21 was found on blasts cells. Complete remission remains after 32 months. DISCUSSION: Congenital leukaemias, with trisomy 21 on blasts cells have a good prognosis that justifies observation before using chemotherapy.

Persistent pulmonary hypertension of the newborn with transposition of the great arteries: successful treatment with bosentan.

Persistent pulmonary hypertension of the newborn (PPHN) occurs in 1-4% of neonates with transposition of the great arteries with intact ventricular septum (TGA/IVS). This association is often lethal. To our knowledge, only eight survivors have been described in the literature, two of whom benefited from extracorporeal membrane oxygenation (ECMO). We report two cases of PPHN complicating a TGA/IVS that were refractory to multiple therapies and resolved 48 hours after initiation of bosentan therapy. Bosentan, an oral dual endothelin-1 receptor antagonist, is a new treatment for pulmonary arterial hypertension that was both effective and safe in these two cases of TGA/IVS with PPHN. To our knowledge, it is the first use of bosentan in newborns.

Relationship between dyspnea increase and ventilatory gas exchange thresholds during exercise in children with surgically corrected heart impairment.

To study the relationship between the onset of an increase in dyspnea and ventilatory threshold (VT) in children with congenital heart impairment, sixteen young subjects underwent a cardiopulmonary exercise test with dyspnea perception and ventilatory gas exchange assessments. Dyspnea score was measured from a visual analogical scale at rest and during each step of an incremental exercise test. Dyspnea score was plotted against oxygen uptake and the onset of an increase in dyspnea (DT) was determined when a brutal disruption occurs on the dyspnea score-oxygen uptake curve. VT was defined from gas exchange according to Beaver's method. The first breakdown point in the oxygen uptake-carbon dioxide production relationship locates VT. Oxygen uptake (V(.-)O (2)), pulmonary ventilation (V(.-)E), heart rate (HR), oxygen pulse (O (2) pulse = V(.-)O (2)/HR), carbon dioxide production (V(.-)CO (2)) and power output (P) were measured both at VT and DT effort level. Results pointed out that there was no significant difference between the cardiorespiratory variables measured respectively at VT and DT: V(.-)O (2) (VTV(.-)O (2) = 16.71 +/- 2.65 vs. DTV(.-)O (2) = 18.34 +/- 5.74 ml x kg (-1) x min (-1)), V(.-)E (VTV(.-)E = 24.33 +/- 6.86 vs. DTV(.-)E = 26.82 +/- 9.59 l x min (-1)), (VTV(.-)CO (2) = 789.31 +/- 165.17 vs. DTV(.-)CO (2) = 924.02 +/- 342.28 ml x min (-1)), HR (VTHR = 116 +/- 10 vs. DTHR = 123 +/- 20 beat x min (-1)), O (2) pulse (VT O (2) pulse = 7.83 +/- 2.00 vs. DT O (2) pulse = 8.01 +/- 2.13 ml x kg (-1) x beat (-1)), and P (VTP = 43 +/- 16 vs. DTP = 52 +/- 27 W). Moreover, the cardiorespiratory variables measured at DT and VT were closely related: V(.-)O (2) (r = 0.64, p < 0.01), V(.-)E (r = 0.51, p < 0.01), HR (r = 0.75, p < 0.02), O (2) pulse (r = 0.90, p < 0.001), and P (r = 0.80, p < 0.01). In addition, according to Bland and Altman's procedure, the onset of dyspnea increase and ventilatory threshold were shown in close agreement for the cardiorespiratory variables measured at these effort levels. The standard errors of the estimates were low. It was concluded that dyspnea and ventilatory gas exchange thresholds occur concomitantly and were strongly correlated in children with congenital heart impairment. The use of the onset of dyspnea increase for aerobic capacity assessment may be a good alternative to ventilatory gas exchange threshold measurement.

Performance and muscle oxygenation during isometric exercise and recovery in children with congenital heart diseases.

This study investigated performance, muscle oxygen saturation (StO2), and blood volume (BV) in patients with congenital heart diseases (CHD) and healthy children during and following sustained exercise. Maximal volunteered contraction (MVC) and endurance at 50 % of MVC (time to exhaustion, Tlim) of the knee extensor were measured in nine patients with CHD and 14 healthy control children. Near infrared spectroscopy was used to evaluated StO2 and BV in vastus lateralis. The drop in muscle oxygen saturation (D(mO2)), half time of recovery (T(SR)), and recovery speed to maximal oxygen saturation (Rs) were analyzed. Patients with CHD showed lower MVC (101.0 +/- 6.2 vs. 125.5 +/- 7.4 N x m, p < 0.01) and Tlim (67.0 +/- 7.5 vs. 127.5 +/- 11.1 s, p < 0.001) than control children. StO2 and BV values in both groups were similar at rest and decreased at the onset of contraction. D(mO2) was larger in patients, which reflected pronounced deoxygenation. During recovery, the patients exhibited a longer TSR (25.2 +/- 2.1 vs. 18.4 +/- 2.0 s, p < 0.05) and R(S) (64.6 +/- 5.5 vs. 42.7 +/- 4.6 s, p < 0.01) than control children. We concluded that reduced strength and endurance in patients with CHD were associated with an impairment of StO2 and BV, and a slower reoxygenation during recovery.

Six-minute walking test to assess exercise tolerance and cardiorespiratory responses during training program in children with congenital heart disease.

This study assessed the exercise tolerance and the cardiorespiratory responses to a training program by the six-minute walk test (6'WT) in children with congenital heart disease (CHD). Seventeen cardiac and 14 healthy children performed maximal cardiopulmonary exercise test (CPET) and 6'WT. Reliability of 6'WT was assessed in all subjects (test-retest) by Bland-Altman plots. Cardiac subjects were randomly divided in training (T-CHD) and control groups (C-CHD). T-CHD underwent an individualized training exercise at the ventilatory threshold (VT) intensity during 12 weeks. We found that the 6'WT is a reliable and reproducible test. CHD children walked a lower distance than healthy children before training (472.5 +/- 18.1 vs. 548.8 +/- 7.7 m, respectively, p < 0.001). Likewise, power output, oxygen uptake (V.O (2)), and heart rate (HR) at the maximum and the VT levels, were significantly lower in patients (p < 0.001). After training, a significant improvement of walking distance (WD) was shown in T-CHD (529.6 +/- 15.3 vs. 467.7 +/- 17.1 m, p < 0.001). The power output, VO2, HR, and V.E increased slightly (6 to 10 %, p > 0.05) at peak exercise and significantly at ventilatory threshold level (p < 0.05) in T-CHD. Significant relationships between WD and VO2max as well as VO2 at VT were founded (p < 0.05). We concluded that the 6'WT is a useful and reliable tool in the assessment and follow-up of functional capacity during rehabilitation program in children with CHD.

Timing and driving components of the breathing strategy in children with cystic fibrosis during exercise.

The aim of this study was twofold: first, to determine the breathing strategies of children with cystic fibrosis (CF) during exercise, and secondly, to see if there was a correlation with lung function parameters. We determined the tension-time index of the inspiratory muscles (T(T0.1)) during exercise in nine children with CF, who were compared with nine healthy children with a similar age distribution. T(T0.1) was determined as followed T(T0.1) = P0.1/PImax . T(I)/T(TOT), where P0.1 is mouth occlusion pressure, PImax is maximal inspiratory pressure, and T(I)/T(TOT) is the duty cycle. CF children showed a significant decrease of their forced expiratory volume in 1 sec (FEV1), forced vital capacity (FCV), and FEV1/FVC, whereas the residual volume to total lung capacity ratio (RV/TLC) ratio and functional residual capacity (FRC) were significantly increased (P < 0.001). Children with CF showed mild malnutrition assessed by actual weight expressed by percentage of ideal weight for height, age, and gender (weight/height ratio; 82.3 +/- 3.6%). Children with CF showed a significant reduction in their PImax (69.3 +/- 4.2 vs. 93.8 +/- 7 cmH2O). We found a negative linear correlation between PImax and weight/height only in children with CF (r = 0.9, P < 0.001). During exercise, P(0.1), P0.1/PImax, and T(T0.1) were significantly higher, for a same percent maximal oxygen uptake in children with CF. On the contrary, T(I)/T(TOT) ratio was significantly lower in children with CF compared with healthy children. At maximal exercise, children with CF showed a T(T0.1) = 0.16 vs. 0.14 in healthy children (P < 0.001). We observed at maximal exercise that P0.1/PImax increased as FEV1/FVC decreased (r = -0.90, P < 0.001), and increased as RV/TLC increased (r = 0.92, P < 0.001) only in children with CF. Inversely, T(I)/T(TOT) decreased as FEV1/FVC decreased (r = 0.89, P < 0.001), and T(I)/T(TOT) decreased as RV/TLC increased (r = -0.94, P < 0.001). These results suggest that children with CF adopted a breathing strategy during exercise in limiting the increase of the duty cycle. Two determinants of this strategy were degrees of airway obstruction and hyperinflation.

[Tachycardia-induced cardiomyopathy in children: a difficult diagnosis but a reversible form of left ventricular dysfunction]. / Myocardiopathie rythmique de l'enfant : un diagnostic difficile mais une forme curable de dysfonction ventriculaire gauche.

UNLABELLED: Tachycardia-induced cardiomyopathy is a reversible left ventricular dysfunction caused by cardiac arrhythmia. Because of its reversibility, a correct diagnosis and treatment are necessary. The aim of our study was to precise the diagnostic procedures of the tachycardia-induced cardiomyopathy and to study the left ventricular function after the correction of the arrhythmia. PATIENTS AND METHODS: A retrospective study done between 1992 and 2001. Children studied were followed-up for: an idiopathic form of cardiomyopathy, in which the etiological research showed a cardiac arrhythmia; a cardiac arrhythmia associated to a cardiomyopathy. An electrocardiogram recorded the cardiac arrhythmia. The left ventricular function was evaluated by an echocardiography before and every month after the correction of the cardiac arrhythmia. RESULTS: Twelve children were included, ages ranged from 2 months to 15 years (median 11 years). Four patients presented a cardiac insufficiency associated to arrhythmia; three followed-up for an arrhythmia developed a cardiomyopathy; five whose cardiac arrhythmia was not easy to demonstrate had an idiopathic form of cardiomyopathy. The Wilcoxon test showed a significant amelioration (P < 0.01) of the left ventricular function after the correction of the cardiac arrhythmia. CONCLUSIONS: Tachycardia-induced cardiomyopathy in children is curable and the diagnosis is quite difficult. Pediatricians and family doctors should try to look for specific signs of cardiac insufficiency or arrhythmia. Pediatric cardiologists should search a tachycardia-induced cardiomyopathy in every idiopathic form of cardiomyopathy.

Should an echocardiographic scan be done routinely for infants of diabetic mothers?

Several cardiologic pathologies are seen in infants of diabetic mothers (IDMs). Though asymmetrical septal hypertrophy (ASH) is a frequent pathology in IDMs, it is not routinely searched for with an echocardiographic scan. We have performed an echocardiographic examination for all IDMs (56 neonates) hospitalized between January 1987 and December 1992 in our neonatology and neonatal reanimation units. Of 56 patients, the diagnosis of 17 cases of ASH 930%) was made. The group with ASH (17 neonates) had a greater corporeal index than the group without ASH (39 neonates) (p < 0.05). Four of the 17 IDMs (24%) with ASH and one of the 39 IDMs (3%) without ASH presented with a cardiac insufficiency (p < 0.05). ASH is a pathology which should be searched for routinely IDMs.

Regulation of sleep and body temperature in response to exposure to cool and warm environments in neonates.

BACKGROUND AND OBJECTIVE: Thermoregulation is impaired during desynchronized sleep in animals and in adults. This can lead to a conflict between homeothermy and sleep in nonthermoneutral conditions. This study aimed to analyze thermoregulation during sleep, especially during desynchronized sleep (active sleep, AS) and to determine whether the conflict between thermoregulation and sleep might exist in the newborn sleeping in warm or cool conditions. METHODS: Esophageal and skin (cheek and abdomen) temperatures, local sweating rate (ventilated sweat collection capsule stuck on the abdomen), metabolism (indirect respiratory calorimetry), and sleep variables were recorded in 10 newborns exposed, in an incubator, to thermoneutral, warm, and cool environments. Body movements and apneas were also considered. Exposures were performed after a first habituation condition. RESULTS: Sleep structure was not modified by the first exposure nor by the warm environment. Exposure to cool temperatures increased AS duration (+13% of total sleep time) and the quantity of body movements during AS (+11.3% of AS duration), whereas these parameters were not modified during quiet sleep. The thermoregulatory response to warm and cool environments was not impaired during AS. During exposure to mild thermal load, analyses revealed large interindividual differences in the strategy for thermoregulation during AS. Depending on the newborn, the thermoregulatory response to cool temperatures could be described by an increase either in nonshivering thermogenesis or in frequency of body movement. In warm conditions, most newborns exhibited an increased sweating rate. The interindividual differences (lack of increase sweating in three newborns) seemed to be linked to changes in the sensitivity of the sweating response. CONCLUSION: Because thermoregulation is not impaired during AS, this sleep stage seems to be a well-protected one from a thermoregulatory point of view. This difference from adults and animals may be due to the important role of AS in newborn's nervous maturation.

Effect of continuous heat exposure on sleep during partial sleep deprivation.

This study examined the effects of continuous heat exposure on sleep structure during a partial sleep-deprivation regime. The experimental protocol was divided into three periods. After a baseline period (5 days and nights at 20 degrees C), the sleep of the subjects was restricted to the second half of the night (3 a.m.-7 a.m.) for four consecutive nights. The restricted-sleep period was followed by two recovery days and nights. During the deprivation and recovery periods, the ambient temperature was 20 degrees C for six of the 12 subjects and 35 degrees C for the others. Sleep, esophageal and mean skin temperatures were continuously recorded. At 20 degrees C, the expected effect of sleep debt was apparent. There were significant reductions in time spent awake and in latencies for sleep and stage 4 sleep. The duration of stage 4 sleep significantly increased during the four successive restricted-sleep nights, whereas esophageal temperature significantly decreased over the successive days. When heat was added, esophageal temperature decrease was weakened, and the significant increase in stage 4 duration seen at 20 degrees C was not found. The findings suggest that the heat load imposed in our experimental condition has a suppressive effect on sleep stage 4 increase, which is induced by sleep restriction. The hypothesis that an increase in this sleep stage serves as a mechanism for energy conservation should be also considered.

Aerobic capacity of competitive ice hockey players 10-15 years old.

Oxygen uptakes (VO2) recorded at anaerobic threshold and at the end of a maximal exercise (VO2 max) and their relation to left ventricular function were analyzed in 11 young ice hockey players during an incremental exercise on a bicycle ergometer. The children, highly trained, participated annually during 6 years (from the age of 10-15 years) in laboratory tests. The maturative status of the subjects was evaluated from peak height velocity (PHV). Heart rate was recorded by electrocardiogram. Oxygen uptake, CO2 production, respiratory frequency, pulmonary ventilation (VE) were recorded at rest and every 30 s during exercise through a Rudolph valve connected to a calibrated oxycon gas analyser. The anaerobic threshold was determined by a non-invasive method from pulmonary ventilation curves. Left ventricular volumes at end-systole and end-diastole were obtained, at rest, by M mode echocardiography. Results showed that both VO2 at anaerobic threshold and VO2max were positively correlated with body mass or with age of PHV. The increments were constant from year to year. At anaerobic threshold, the ratio VO2/VO2max was independent of maturative age. Similar findings were observed when considering VE except after the years of PHV where there was a remarkable increase in pulmonary ventilation. The results indicate that the growth of each cardiorespiratory component is optimalized with body size increase in order to keep constant the aerobic response to exercise. As judged by the explained variance of the different linear regression analyses between resting left ventricular dimensions and VO2, cardiac volume was of minimal importance in determining VO2. In the postpubertal period, stroke volume accounted for 26.7% of VO2 at anaerobic threshold and 30.0% of VO2max. This suggests that local changes occurring at muscular level are of paramount importance in determining the aerobic capacity of highly trained boys.

[Infectious endocarditis on permanent endocavitary pacemakers: value of echocardiography and review of the literature]. / Endocardites infectieuses sur sondes de stimulation endocavitaire permanentes: intérêt de l'échocardiographie et revue de la littérature.

Infectious endocarditis around indwelling pacemakers is rare (0.15% of all implantations). They have a gloomy prognosis with a global mortality rate of nearly 34% as emerges from this review of the literature concerning 58 cases of infectious endocarditis published within the past 16 years. On the basis of the 6 cases which the authors report, they stress the importance and sometimes difficulty of using ultrasound in a positive diagnosis. Cardiographic ultrasound, which can determine the size and emboligenic nature of vegetations is capital in choosing how to remove the pacemakers. Percutaneous ablation by simply pulling or by catheterization currently gives the best results, but it may be necessary to resort to surgery involving right atriotomy if emboligenic vegetations are present. By combining antibiotic treatment and ablation of the intracavitary material, a cure is obtained in 92% of cases. These figures should be compared with the lack of success of using antibiotic treatment alone which results in a high level of mortality (84%).

Ligation of the patent ductus arteriosus in premature infants--indications and procedures.

Premature newborns with patent ductus arteriosus can be managed by prostaglandin inhibition, but this medical treatment carries a high risk of renal failure, and other complications such as necrotizing enterocolitis and hematologic disorders have been described. Echocardiography gives an early confirmation of shunt and surgical treatment may be proposed. The aortic arch anatomy in the premature infant may not be as simple to determine as the anatomy of an older child. In the premature infant the use of a clip for patent ductus arterious closure seems the best technique, avoiding circular dissection of the ductus. We report our experience of 68 cases operated upon.

Maximal oxygen uptake and aerobic-anaerobic transition on treadmill and bicycle in triathletes.

The maximal aerobic capacity and the aerobic-anaerobic transition were analyzed on 14 triathletes performing an incremental work load on a bicycle ergometer and on horizontal or inclined treadmills. To compared the cardiorespiratory responses between cycling and running, the subjects were divided into 2 groups of 7 with similar aerobic capacity determined from cycle runs. The first group ran on horizontal treadmill while the second group performed similar exercise on inclined treadmill at constant grade (1.5%). Heart rate was recorded by electrocardiogram. Oxygen uptake (VO2), CO2 production (VCO2), respiratory frequency, and pulmonary ventilation were monitored at 30 s intervals through a Rudolph valve connected to a calibrated Oxycon V. Tidal volume, respiratory exchange ratio, equivalent O2 and CO2 were calculated from on-line computer. Aerobic and anaerobic thresholds were determined by a non-invasive method from pulmonary ventilation curves. The results showed that maximum oxygen uptake (VO2max) did not differ between the 2 types of ergometers. Pulmonary ventilation, heart rate and VO2 recorded at aerobic and anaerobic thresholds depended on the mode of exercise and reached the highest values on inclined treadmill. The amount of muscle mass, the type and the distribution of active motor units involved in each exercise test might be at the origin of these differences. This indicates that, when assessing a training program from anaerobic threshold values, it is necessary to take into consideration the type of ergometer used and the protocol performed.