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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. [Copyright &y& Elsevier]

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., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)

We investigated the effect of training on peripheral muscular performance and oxygenation during exercise and recovery in children with congenital heart diseases (CHD). Eighteen patients with CHD aged 12 to 15 years were randomly assigned into either an individualized 12-week aerobic cycling training group (TG) or a control group (CG). Maximal voluntary contraction (MVC) and endurance at 50% MVC (time to exhaustion, T(lim)) of the knee extensors were measured before and after training. During the 50% MVC exercise and recovery, near-infrared spectroscopy (NIRS) was used to assess the fall in muscle oxygenation, i.e., deoxygenation ([Formula: see text]) of the vastus lateralis, the mean rate of decrease in muscle oxygenation, the half time of recovery (T(1/2R)), and the recovery speed to maximal oxygenation (R(S)). There was no effect of time on any parameter in the CG. After training, significant improvements were observed in TG for MVC (101.6 ± 14.0 vs. 120.2 ± 19.4 N·m, p < 0.01) and T(lim) (66.2 ± 22.6 vs. 86.0 ± 23.0 s, p< 0.01). Increased oxygenation (0.20 ± 0.13 vs. 0.15 ± 0.07 a.u., p < 0.01) and faster mean rate of decrease in muscle oxygenation were also shown after training in TG (1.22 ± 0.45 vs. 1.71 ± 0.78%·s(-1), p < 0.001). Moreover, a shorter recovery time was observed in TG after training for T(1/2R) (27.2 ± 6.1 vs. 20.8 ± 4.2 s, p < 0.01) and R(S) (63.1 ± 18.4 vs. 50.3 ± 11.4 s, p < 0.01). A significant relationship between the change in [Formula: see text] and both MVC (r = 0.95, p < 0.001) and T(lim) (r = 0.90, p < 0.001) in TG was observed. We concluded that exercise training improves peripheral muscular function by enhancing strength and endurance performance in children with CHD. This improvement was associated with increased oxygenation of peripheral muscles and faster recovery.

The present investigation was aimed at assessing the effect of home-based training on cardiorespiratory responses in children surgically corrected for congenital heart impairment using dyspnea threshold (DT) as training intensity. A group of 23 children aged 15 +/- 1.4 years who had undergone surgical correction for congenital heart disease (CHD group) and 12 healthy children used as a control group performed an exercise protocol during which aerobic capacity, ventilatory threshold (VT), and DT were assessed. Afterwards, the CHD group was divided into two subgroups: trained and untrained subjects. Training sessions over a period of 2 months were performed at an intensity corresponding to DT by the CHD trained group. Dyspnea was scored according to a visual analog scale during the warm up, at each exercise stage, and during the recovery period. DT was located on the oxygen uptake/dyspnea curve when a sudden increase in the dyspnea score occured, while VT was defined according to the methodology previously employed by Beaver and colleagues. The results showed that children who had undergone surgery for CHD had reduced aerobic capacity. No significant difference was observed between VT and DT in children corrected for CHD. These two thresholds were highly related. Home-based training at DT did not strongly improve aerobic capacity nor did it influence the relationship between VT and DT. Further studies should be conducted to confirm these preliminary findings, particularly when aerobic capacity is improved by training.

Background: It is well known that severe lung impairment in cystic fibrosis (CF) may compromise respiratory muscle function at rest. Even though patients with CF and severe obstructive lung disease exhibit an abnormal breathing pattern during exercise (due to expiratory flow limitation), patients with CF and normal lung function reportedly have a normal breathing pattern., Objectives: The aim of the study was to assess the precise characteristics of the ventilatory pattern adopted during exercise by children with CF and mild to moderate lung disease., Methods: Nine children diagnosed as having mild to moderate CF and 9 healthy children with a similar age distribution participated in this study. Both groups performed a continuous incremental cycling protocol. Breathing and timing components were assessed during exercise., Results: Differences in the breathing pattern between children with CF and controls during exercise are illustrated in Hey plot which described a rapid shallow breathing pattern in children with CF. During exercise, children with CF showed a significantly lower mean inspiratory flow than healthy children (p < 0.001), whereas the mean expiratory flow was higher (p < 0.001). Children with CF also showed a significant increase in the end-tidal carbon dioxide pressure, which may indicate the emergence of hypercapnia., Conclusions: During exercise, children with CF (even those not suffering from advanced disease) showed signs of rapid, shallow breathing and an increase in the ventilatory response. This was essentially due to an increase in the mean inspiratory flow, which in turn suggests an expiratory flow limitation. The children were also predisposed to hypercapnia., (Copyright (c) 2008 S. Karger AG, Basel)

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.

Background: Diminished aerobic capacity and weakness of both respiratory and peripheral muscles have been observed in cardiac patients and may contribute to exercise limitation. The aim of this study was to evaluate the effects of a home-based training programme on aerobic fitness and oxygenation of the respiratory muscles in children with congenital heart disease (CHD)., Methods and Results: Eighteen patients with CHD aged 12-15 years participated in this study. Ten patients (training group, TG) underwent a training programme for 12 weeks and eight patients served as a non-training control group (CG). All subjects performed a cardiopulmonary exercise test before and after the study period. Oxygenation of the respiratory muscles was assessed using near-infrared spectroscopy. No significant differences were observed, at baseline and after the completion of the study, between the CG and TG in peak exercise workload, oxygen uptake (VO2), carbon dioxide output (VCO2), pulmonary ventilation (VE), and heart rate (HR). However, a significant improvement in exercise performance was found in the TG versus the CG when results were compared at the ventilatory threshold (Vth): workload (45.2+/-8.0 versus 58.5+/-7.4%; P<0.05), VO2 (62.3+/-7.5 versus 69.8+/-5.1%; P<0.05), VCO2 (49.8+/-5.7 versus 60.0+/-5.8%; P<0.05), VE (42.8+/-9.9 versus 50.1+/-9.5%; P<0.05), and HR (69.5+/-6.1 versus 76.0+/-3.5%; P<0.05). After training, an improvement in oxygenation of the respiratory muscles was found in the TG from 60% of VO2max until the end of exercise. At the Vth, the TG showed greater oxygenation after training (55.1+/-6.6 versus 43.0+/-6.9%, P<0.01, respectively). Furthermore, we showed a significant correlation of the change in respiratory muscle oxygenation and VO2 in the TG (r=0.90, P<0.01)., Conclusion: It is concluded that general physical training at submaximal intensity induces better aerobic fitness and improves respiratory muscle oxygenation in children with CHD.

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.

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 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%).

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.

A heart volume overload model was developed in male New Zealand rabbit nine weeks old, using femorofemoral or jugulo-carotid fistulae, producing 50% increase of the mean cardiac output. An evaluation was performed after 2 and 11 weeks. It was evaluated by dimensional echocardiogram and doppler system flow measurement at the aorta ring, angiography and right cardiac pressure recording. This hemodynamic analysis was completed by a heart and fistulae histopathological study. In some volume overload cases, an increasing volume index parameter was described. Two weeks later an increase of the cardiac frequency and a dilatation of the aorta ring were observed but the stroke volume remained unchanged. 11 old weeks fistula animals presented similar frequency and stroke volume. So, the heart compensatory mechanisms varied with the age of the rabbit. The right catheter and cardiac angiography were not useful for ventricular volume overload estimation. Histopathological study showed parenchymal changes and alveolo capillary congestion. An increase of the heart weight/body weight ratio was described. When analysed by ultrasound and blood flow measurement, data were similar to those obtained by invasive pressure recordings or by dilution system. An experimental model of overload volume in rabbit with non invasive recording methods (bidimensional ultrasound and doppler system) can be proposed.

The modalities of left ventricular (LV) adaptation (dilatation and/or hypertrophy) to exercise are not as well known in children as in adults. Therefore, the authors followed up 11 national ice hockey players, initially aged 10, following an eight hour per week training schedule for a period of 5 years. M mode echocardiographic studies were carried out each year during the training period to measure LV internal dimensions, wall thickness, myocardial mass and contractility (fractional shortening and systolic stress index). The evolution of these parameters was evaluated (Student's test) by two year peripubertal periods (10-12 years: 12-14 years) and compared in absolute values and in rate of growth with the standardised values indexed to body surface area reported by Henry. Between 10 and 12 years of age, the LV internal dimensions (a good indicator of LV volume in healthy children) increased significantly (p less than 0.05) and LV mass increased very significantly (p less than 0.01). The LV internal dimensions were normal at the outset and remained in the upper limits of normality reported by Henry with a normal rate of growth. Myocardial mass was normal at the age of 10 and its rate of growth was also normal. Between 12 and 14 years of age, the increase in LV internal dimensions was not statistically significant but myocardial mass increased very significantly (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)