Impact of COVID-19 disease on clinical research in pediatric and congenital cardiology.

BACKGROUND: COVID-19 triggered an unprecedented crisis affecting society at every level. Research in pediatric and congenital cardiology is currently in full development and may have been disrupted. The aim of the study was to determine the impact of COVID-19 on pediatric and congenital cardiology clinical research and to analyze decision-making and adaptation processes, from a panel of ongoing academic and industry-sponsored research at the time of the pandemic. METHODS: This observational study was carried out in April 2020, from a CHD clinical research network involving five tertiary care pediatric and congenital cardiology centers. Investigators and clinical research assistants from each participating research center completed an online survey questionnaire, and each principal investigator underwent a 1-h web-based videoconference interview. RESULTS: A total of 34 study questionnaires were collected, reporting that 18 studies were totally suspended. Upon the investigator's decision, after discussion on ethical issues and with facilitating support from health authorities, 16 studies were resumed. The rate of study suspension in interventional research (53%) was similar to that in non-interventional research (56%). Logistical problems were predominantly reported in both continued and suspended trials. Research protocols were adapted, largely thanks to telemedicine, which in some cases even improved the course of the study. CONCLUSION: The impact of the COVID-19 pandemic on clinical research in pediatric and congenital cardiology has been limited by a rapid adaptation of all research structures and an extensive use of telemedicine at all stages of the studies.

Dermatological manifestations in Noonan syndrome: a prospective multicentric study of 129 patients positive for mutation.

BACKGROUND: Data on dermatological manifestations of Noonan syndrome (NS) remain heterogeneous and are based on limited dermatological expertise. OBJECTIVES: To describe the dermatological manifestations of NS, compare them with the literature findings, and test for dermatological phenotype-genotype correlations with or without the presence of PTPN11 mutations. METHODS: We performed a large 4-year, prospective, multicentric, collaborative dermatological and genetic study. RESULTS: Overall, 129 patients with NS were enrolled, including 65 patients with PTPN11-NS, 34 patients with PTPN11-NS with multiple lentigines (NSML), and 30 patients with NS who had a mutation other than PTPN11. Easy bruising was the most frequent dermatological finding in PTPN11-NS, present in 53·8% of patients. Multiple lentigines and café-au-lait macules (n ≥ 3) were present in 94% and 80% of cases of NSML linked to specific mutations of PTPN11, respectively. Atypical forms of NSML could be associated with NS with RAF1 or NRAS mutations. In univariate analysis, patients without a PTPN11 mutation showed (i) a significantly higher frequency of keratinization disorders (P = 0·001), including keratosis pilaris (P = 0·005), ulerythema ophryogenes (P = 0·0001) and palmar and/or plantar hyperkeratosis (P = 0·06, trend association), and (ii) a significantly higher frequency of scarce scalp hair (P = 0·035) and scarce or absent eyelashes (P = 0·06, trend association) than those with PTPN11 mutations. CONCLUSIONS: The cutaneous phenotype of NS with a PTPN11 mutation is generally mild and nonspecific, whereas the absence of a PTPN11 mutation is associated with a high frequency of keratinization disorders and hair abnormalities.

[Cardiac rehabilitation in adults with congenital heart diseases]. / Réadaptation cardiaque des adultes avec cardiopathies congénitales.

The great advances in the medical and surgical management of congenital heart diseases have allowed many children to reach adulthood with often a good hemodynamic result. Nevertheless most of these adults have a limitation of their functional capacity. This limitation is more or less important, penalizes them in their daily life and alters their quality of life. The origin of this limitation is generally multifactorial. It is linked, of course, to the severity of the heart disease and the quality of the operative result. But there is very often a physical deconditioning. It can be secondary to the heart disease but is often secondary to a lack of physical activity. It is the parents, sometimes overprotective, but frequently the doctors who imposed, often wrongly, this restriction. It is essential to take this dimension into account in view of the important benefits expected for health and quality of life. Cardiac rehabilitation is a privileged tool for providing advice in a suitable environment. This requires close collaboration between cardiac rehabilitators and congenital cardiologists to offer appropriate care. We bring here some reflections and the basic elements to guide the re-training of these patients.

Correlation between cardio-pulmonary exercise test variables and health-related quality of life among children with congenital heart diseases.

BACKGROUND: Health-related quality of life (HR-QoL) stands as a determinant "patient-related outcome" and correlates with cardio-pulmonary exercise test (CPET) in adults with chronic heart failure or with a congenital heart disease (CHD). No such correlation has been established in pediatric cardiology. METHODS AND RESULTS: 202 CHD children aged 8 to 18 performed a CPET (treadmill n=96, cycle-ergometer n=106). CHD severity was stratified into 4 groups. All children and parents filled out the Kidscreen HR-QoL questionnaire. Peak VO2, anaerobic threshold (AT), and oxygen pulse followed a downward significant trend with increasing CHD severity and conversely for VE/VCO2 slope. Self-reported and parent-reported physical well-being HR-QoL scores correlated with peak VO2 (respectively r=0.27, p<0.0001 and r=0.43, p<0.0001), percentage of predicted peak VO2 (r=0.28, p=0.0001 and r=0.41, p<0.0001), and percentage of predicted VO2 at AT (r=0.22, p<0.01 and r=0.31, p<0.0001). Significant correlations were also observed between several HR-QoL dimensions and dead space to tidal volume ratio (VD/VT), oxygen uptake efficiency slope (OUES), oxygen pulse but never with VE/VCO2 slope. The strongest correlations were observed in the treadmill group, especially between peak VO2 and physical well-being for parents (r=0.57, p<0.0001) and self (r=0.40, p<0.0001) reported HR-QoL. CONCLUSIONS: Peak VO2 and AT are the two CPET variables that best correlated with HR-QoL in this large pediatric cohort, parents' reports being more accurate. If HR-QoL is involved as a "PRO" in a pediatric cardiology clinical trial, we suggest using parents related physical well-being HR-QoL scores. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (number NCT01202916).

Quality of Life of Children with Congenital Heart Diseases: A Multicenter Controlled Cross-Sectional Study.

To assess the health-related quality of life (QoL) in children with congenital heart diseases (CHD) with a validated questionnaire in comparison with control children. We prospectively recruited 282 children with CHD aged from 8 to 18 years in two tertiary care centers (France and Belgium) and 180 same-age controls in randomly selected French schools. Children's QoL was self-reported with the KIDSCREEN-52 questionnaire and reported by parents with the KIDSCREEN-27. QoL scores of each dimension were compared between CHD and controls and between the classes of disease severity. Both centers were comparable for most demographic and clinical data. Age- and gender-adjusted self-reported QoL scores were lower in CHD children than in controls for physical well-being (mean ± SEM 45.97 ± 0.57 vs 50.16 ± 0.71, p < 0.0001), financial resources (45.72 ± 0.70 vs 48.85 ± 0.87, p = 0.01), peers/social support (48.01 ± 0.72 vs 51.02 ± 0.88, p = 0.01), and autonomy in the multivariate analysis (47.63 ± 0.69 vs 49.28 ± 0.85, p = 0.04). Parents-reported scores were lower in CHD children for physical (p < 0.0001), psychological well-being (p = 0.04), peers/social support (p < 0.0001), and school environment (p < 0.0001) dimensions. Similarly, the disease severity had an impact on physical well-being (p < 0.001), financial resources (p = 0.05), and peers/social support (p = 0.01) for self-reported dimensions, and on physical well-being (p < 0.001), psychological well-being (p < 0.01), peers/social support (p < 0.001), and school environment (p < 0.001) for parents-reported dimensions. However, in multivariate analysis on self-reported QoL, disease severity was significantly associated with the self-perception dimension only. Self-reported QoL of CHD children was similar to that of same-age healthy children in seven of 10 dimensions, but parents-reported QoL was impaired in four of five dimensions.

[Hypertension in the absence of renal involvement during childhood Henoch-Schönlein purpura]. / Hypertension artérielle sans atteinte rénale au cours d'un purpura rhumatoïde de l'enfant.

Henoch-Schönlein purpura (HSP) is an IgA mediated vasculitis that affects small vessels. In this condition, arterial hypertension is most often linked with renal involvement, but it can also occur in the absence of urinary abnormalities. We report the case of a 12-year-old girl who presented with HSP and hypertension in the absence of renal involvement. Hypertension responded to oral therapy with nicardipine, and disappeared after healing of the disease. In the case of hypertension during HSP in the absence of renal involvement, other causes of childhood's arterial hypertension have to be ruled out.

[Value of the Norwood-Sano compared with the classical Norwood procedure in hypoplastic left heart syndrome]. / Intérêt de l'intervention de Norwood-Sano par rapport à l'intervention classique de Norwood dans l'hypoplasie du coeur gauche.

Palliative treatment of the hypoplastic left heart syndrome is rarely practiced in France because of the poor prognosis of the first surgical stage of the Norwood procedure. The recent modification proposed by Sano seems to give more promising results. The authors report their experience with the Norwood-Sano procedure compared with the classical Norwood procedure in 13 neonates with hypoplasia of the left heart. From 1999 to 2005, 8 patients underwent the classical Norwood procedure (1999-2001) and 5 had the Sano modification (2002-2005). During the preoperative period, there was 1 case of a very restrictive interatrial septum and 5 patients required mechanical ventilation. The patients were operated at an average age of 8.5 +/- 12 days. The results showed that survival after the first surgical stage was significantly better with the Sano modification (12.5% versus 80%; p= 0.03). All patients who survived the first stage went on to the second stage with a bi-directional right superior cavo-pulmonary derivation at an average of 6.1 +/- 2.4 months. Despite the infundibulotomy of the Sano modification, no arrhythmia or right ventricular dysfunction was observed after an average follow-up of 21.7 +/- 7.6 months. The authors conclude that the Sano modification improved survival of patients with hypoplasia of the left heart after the first palliative surgical procedure. The long-term follow-up of patients operated by this technique should particularly look out for arrhythmias and right ventricular dysfunction.

[Digoxin-Josamycin: a dangerous drug interaction in children]. / Digoxine-Josamycine: une interaction dangereuse chez l'enfant.

Digitalis intoxication is usually accidental in children. We report the case of a young infant with congenital heart disease in whom the coadministration of digoxin and josamycin led to a 50% increase in the digoxin concentration, generating sinoatrial block and cardiac failure. Clinical and electrocardiographic symptoms very quickly resolved following immunotherapy with antidigitalis Fab fragments. Digoxin concentrations must be carefully monitored in patients concomitantly receiving macrolides to ensure that the digoxin dose can be readjusted if necessary.

Permanent junctional reciprocating tachycardia in children: a multicentre study on clinical profile and outcome.

OBJECTIVES: To investigate the clinical profile, natural history, and optimal management of persistent or permanent junctional reciprocating tachycardia (PJRT) in children. METHODS AND RESULTS: 85 patients meeting the ECG criteria for PJRT were enrolled in a retrospective multicentre study. Age at diagnosis varied from birth to 20 years (median 3 months). Follow up ranged from 0.1 to 26.0 (median 8.2) years. At the time of referral, 24 of 85 patients (28%) had congestive heart failure that was resolved with medical treatment in all patients. Eighty three patients received drug treatment initially. Amiodarone and verapamil were the most effective with a success rate of 84-94% alone or in association with digoxin. Radiofrequency ablation of the accessory pathway was performed in 18 patients. There was a trend for a relation between age at ablation and the result of the procedure, failures being more common in younger patients (three of six procedures in younger and 15 of 18 in older children were successful; p = 0.14). Two patients with persistent left ventricular dysfunction on echocardiography but with no symptoms of congestive heart failure died suddenly one month and three years after diagnosis. PJRT resolved spontaneously in 19 patients (22%). Age at diagnosis of PJRT was not a predictor of spontaneous resolution. CONCLUSIONS: PJRT is a potentially lethal arrhythmia in children with tachycardia induced cardiomyopathy. Spontaneous resolution of tachycardia is not uncommon. Antiarrhythmic treatment is often effective. Radiofrequency ablation should be performed in older children or when rate is not controlled, especially in patients with persistent left ventricular dysfunction.

[Medico-surgical treatment of occlusion of the left pulmonary artery by extension of ductal tissue (pulmonary coarctation)]. / Traitement médico-chirurgical de l'occlusion de l'artère pulmonaire gauche par extension de tissu ductal (coarctation pulmonaire).

The authors report the results of surgical treatment completed by interventional catheterisation of occlusion of the left pulmonary artery by extension of ductal tissue. Since 2001, 7 patients operated for occlusive coarctation of the left pulmonary artery at an average age of 11 months (3 to 37 months) had a restenosis. The cardiac malformation was pulmonary atresia with ventricular septal defect (N=4), tetralofy of Fallot (N=2) and critical pulmonary valvular stenosis (N=1). Pulmonary artery surgery consisted of resection anastomosis in 4 cases and a plasty in 3 cases. A primary angioplasty was performed 5 to 170 months (median 12 months) later, at an average age and weight of 3.4 years (0.7 to 16.9 years) and 14 Kg (8 to 52 Kg) with implantation of 3 stents. The median diameter increased from 5 mm (1 to 9 mm) to 10 mm (6 to 16 mm). Tc-99m scintigraphy showed an increase in mean left pulmonary perfusion from 9% (6 to 28%) to 28% (18 to 42%). Secondarily, 3 repeat angioplasties were necessary with a total of 6 stents implanted in 7 patients. After an average of 2.9 years (0.8 to 6.3 years) follow-up, the patients were asymptomatic with normal right ventricular pressures and a mean left pulmonary perfusion of 33% (24 to 45%). The authors conclude that the treatment of left pulmonary occlusion by coarctation requires a medico-surgical approach in which angioplasty and stenting complete successfully the surgical revascularisation.

Haemodynamic features during high-frequency oscillatory ventilation in preterms.

AIM: To compare the haemodynamic status during high-frequency oscillatory ventilation and conventional mechanical ventilation in very preterm infants with respiratory distress syndrome. METHODS: Thirty-two neonates of less than 30 wk gestation randomly assigned to high-frequency oscillatory ventilation (n = 15) or conventional mechanical ventilation (n = 17) had three echocardiographies and one cerebral Doppler-echography under the same ventilation during the first 48 h of life. RESULTS: Mean airway pressure was 2 cm H2O higher in infants ventilated with high-frequency oscillatory ventilation at the different echocardiographies. Comparable right ventricular indexes were observed in the two groups. Reduction of the ductus arteriosus diameter and ductal closure were significant only in neonates ventilated conventionally. Left ventricular performance and left ventricular contractility did not differ between the groups. The high-frequency group had lower end diastolic velocity and a higher resistance index in the anterior cerebral artery. CONCLUSION: Compared with conventional mechanical ventilation, high-frequency oscillatory ventilation was achieved without altering cardiac function. However, the inability of the left ventricle to improve its performance in the presence of a significant ductal shunt suggests a narrow range of optimal pressures under this ventilatory mode.

[Outcome of infants with hypoplastic left heart syndrome diagnosed in utero]. / Devenir des enfants atteints d'une hypoplasie du coeur gauche diagnostiquée in utero.

The authors report the results of prenatal diagnosis of the hypoplastic left heart syndrome since 1998 in the University Hospitals of Marseille and Montpellier. Twenty-four prenatal diagnoses of this condition were made in mothers with a mean age of 29 (18 to 40 years) and after a mean term of 22 (18.5 to 33) weeks of amenorrhea. Seventeen therapeutic abortions were carried out and 7 neonates born after a mean term of 39 (28 to 40) weeks, were admitted to the paediatric intensive care unit. Two patients required ventilatory assistance with one early death. The other patients were stable after surgery. A Norwood (first stage) procedure was carried out in 6 neonates at a mean age of 5 (1 to 6) days. There was only one survivor (17%). Prenatal diagnosis of the hypoplastic left heart syndrome allows cardiac and extracardiac evaluation of foetuses with this condition. Therapeutic abortions may be proposed and was the commonest choice of the parents in this study. On the other hand, despite better management of neonates with this prenatal diagnosis, the poor prognosis of the Norwood first stage procedure is unchanged. A systematic search for a restriction of the foramen ovale on foetal echocardiography could optimise neonatal management of this problem.

[Short and medium-term results of the Norwood intervention (first stage)]. / Résultats à court et moyen termes de l'intervention de Norwood (première étape).

We report the short and mid-term results of the Norwood procedure (Stage one) in 20 patients with hypoplastic left heart syndrome or univentricular heart with aortic obstruction. Seven patients were prenatally diagnosed. Preoperatively there was obstruction to pulmonary venous return in 6 cases, a mild to moderate tricuspid regurgitation in 6 cases, and 11 patients were supported by mechanical ventilation with multiorgan failure in 5 cases. The surgery was performed under cardiopulmonary bypass at a mean age and weight of 12.9 days and 3 kg, respectively. Nine patients (45%) died within 30 days postoperatively, whereas 5 had delayed sternal closure. The mean duration of mechanical ventilation and ICU stay were 5.7 and 11 days, respectively. Two patients were reoperated for bronchial compression and tracheotomy. Systemic venous thrombosis occurred in 5 patients. In multivariate analysis, an older age at surgery was correlated with postoperative hospital death (p = 0.03). Among the 11 patients discharged home after Stage one procedure, 5 patients underwent balloon dilation for recoarctation and one patient died at home. A bidirectional cavopulmonary anastomosis was performed in 8 patients at a mean age of 0.76 year, with one postoperative death. After a mean follow-up of 1 year (+/- 1.97 years), the 9 remaining patients are all in NYHA class I, at a mean age of 2.2 years. Their mean transcutaneous saturation is 81%. The Norwood procedure (Stage one) is associated with high hospital mortality. However, the functional status of the survivors is correct, like in patients with other type of univentricular hearts. Moreover, although the causes of death in our patients are often not clarified, other studies show that the leading causes of deaths in our patients are often not clarified, other studies show that the leading causes of death in those patients are correctable. In conclusion, the option of a Norwood procedure (Stage one) should be proposed in patients with hypoplastic left heart syndrome (or variant).

Anaerobic fitness in children with asthma: adaptation to maximal intermittent short exercise.

Nineteen asthmatic boys (aged 13.4 years, 25-75 percentile: 11.5-15.1 years) performed short bouts of maximal exercise (force-velocity test) to test their anaerobic fitness and tolerance of maximal anaerobic exercise. Fourteen healthy boys (aged 13.9 years, 25-75 percentile: 11.6-15.7 years) matched for anthropometric characteristics including lean body mass (LBM), pubertal stage, and weekly physical activity formed a control group. The maximal anaerobic power (W(ana)) was measured during the force-velocity test. The maximal oxygen uptake (V'(O2max)) was assessed during a standard graded exercise test. Pre- and post-exercise pulmonary function was measured by body plethysmography. The asthmatic children exhibited lower W(ana) than the control group (8.2 watt.kg(-1) LBM, 25-75 percentile: 7.55-10.6 vs. 11.3 watt.kg(-1) LBM, 25-75 percentile: 9.46-14.1; P = 0.01). V'(O2max) was also diminished in the asthmatic group (P = 0.01). Multiple stepwise regression models revealed that Tanner's score (P < 0.001) and the diagnosis of asthma (P < 0.01) were the best predictors of W(ana). In conclusion, a diminished anaerobic fitness could contribute to the overall exercise limitation in asthmatic children.

[Digitalis intoxication during the neonatal period: role of dehydration]. / Intoxication digitalique en période néonatale: rôle de la déshydratation.

BACKGROUND: Despite the great progress which has been made in the treatment of acute digitalis intoxication by digoxin-immune Fab, it still remains a severe complication of cardiotonic therapy. CASE REPORT: A neonate with ventricular septal defect and large left-to-right shunt was treated with digitalis and diuretics at the usual starting doses. An intensive phototherapy was also required because of a hyperbilirubinemia due to glucose-6-phosphate dehydrogenase deficiency. Toxic digoxin accumulation (plasma level 14 ng/mL) was diagnosed three days after the initiation of treatment by the presence of sinus bradycardia and bursts of ventricular fibrillation. Intravenous administration of digoxin-specific antibody Fab fragments (Digidot) was effective, with a rapid improvement of the digitalis poisoning. CONCLUSION: Because of the particularities concerning drug distribution, metabolism and elimination of drugs in the neonatal period, the digoxin therapeutic index is narrow. This case report suggests the involvement of phototherapy and diuretics, which might induce a significant decrease in extracellular water and drug distribution volumes, ultimately promoting the occurrence of an intoxication.

[Association of severe bronchial disease (bronchial casts, bronchiectasis) and partial abnormal pulmonary venous drainage in 2 children with Turner's syndrome]. / Association d'une bronchopathie sévère (moules bronchiques, dilatation des bronches) et d'un retour veineux pulmonaire anormal partiel à un syndrome de Turner chez deux enfants.

UNLABELLED: The prevalence of cardiovascular malformation is high in Turner's syndrome. We report two cases of partial anomalous pulmonary venous drainage associated with a severe bronchial disease. CASE REPORTS: Case 1: a 5-year-old girl with monosomy X presented with acute respiratory failure. The chest X-ray showed an atelectasis of the left lower lobe. The patient improved following bronchoscopic removal of a bronchial cast. During hospitalization, an anomalous pulmonary venous drainage of the right lung was discovered. In spite of complete surgical repair of the cardiac malformation, several episodes of respiratory failure occurred several years after the operation. Case 2: a 9-year-old girl with monosomy X and coarctation of the aorta underwent pre-operative cardiac catheterization. She had a history of bronchiectasis, leading to a lobectomy. Her respiratory condition improved following surgery. A partial anomalous pulmonary venous return was discovered during the cardiac angiography. The coarctation was repaired surgically. The correction of the left-to-right shunt was not necessary. CONCLUSION: The partial anomalous pulmonary venous return is frequently reported in Turner's syndrome. The possible respiratory disease associated with this cardiac malformation is usually described as a consequence of the increase in pulmonary blood flow. Our two cases did not match this hypothesis.

[Congenital atrioventricular block]. / Le bloc auriculoventriculaire congénital.

Congenital atrioventricular block is defined (Yater) as a documented conduction defect in a young subject with unquestionable bradycardia in the absence of a history of infection which might have caused the condition after birth. It is a rare condition (1 out of 20,000 births) and may be isolated or associated with another congenital malformation. Four cardiac malformations are classically associated: endomyocardial fibrosis, morphological abnormalities close to the conduction system: corrected transposition, left isomerism; patent ductus arteriosus and atrial septal defect apparently unrelated but the most common; the association of mitral regurgitation in adults, although the significance is not very clear. Isolated block is often observed in patients with mothers suffering from autoimmune disease, often clinically latent. Anti Ro/SS-A and La/SS-B antibodies cross into the foetal circulation and cause inflammation of the conduction tissues but the causal mechanism is not known. The diagnosis of the conduction defect is sometimes made during foetal life by echocardiography. After birth, the diagnosis is made by electrocardiography but the block is not always complete or permanent, its degree often increasing with time. In addition, in advanced degrees of block, the escape rhythm tends to slow down. Long-term follow-up studies have revised the previously considered good prognosis of isolated congenital atrioventricular block but advances in cardiac pacing provide satisfactory treatment. In the foetus, isolated atrioventricular block is usually associated with an escape rhythm > 60/min and enables normal vaginal delivery; a low heart rate < 55/min and anasarca carry a poor prognosis. In the neonate, pacing is indicated in babies with cardiac failure and a heart rate < 55/min. Follow-up by Holter monitoring, exercise testing and echocardiography is justified in children and adolescents; the patients may become symptomatic at any age. Pacing is essential in symptomatic cases (malaise, ventricular dysfunction) and useful in cases with long QT intervals, frequent ventricular extrasystoles and wide ventriculogrammes. Pacing is not always easy in children. Epicardial pacing by thoracotomy or an epigastric approach is possible but endocavitary pacing is to be preferred using thin pacing catheters introduced via the subclavian vein and small pacemakers implanted in a sub or prepectoral site. A pacing mode which restores the normal atrioventricular sequence is theoretically superior to single ventricular pacing even if rate responsive frequency.

Determinants of the tension-time index of inspiratory muscles in children with cystic fibrosis.

Nutritional status and chronic pulmonary hyperinflation can alter respiratory muscle function in cystic fibrosis (CF). This study investigated: 1) whether inspiratory muscle function is reduced in children with stable CF in comparison with healthy controls; and 2) the mechanisms leading to inspiratory muscle weakness, which probably predispose to respiratory muscle fatigue. We determined the tension-time index of the inspiratory muscles (TTMUS) noninvasively at rest in 16 children with mild to moderate CF (mean age, 11 +/- 2 years) and 10 healthy controls (mean age, 11 +/- 2 years). The TTMUS was determined as follows: TTMUS = TI/TTOT.PI/PIMAX, where PI is the mean inspiratory pressure estimated from the measure of mouth occlusion pressure (P0.1), PIMAX is the maximal inspiratory pressure, and TI/TOT is the duty cycle. The results showed similar nutritional status in both groups, as well as mild to moderate airway obstruction, hyperinflation, and trapped gas in the CF group. In this group only, a significant inverse relationship was found between TI/TOT and PI/PIMAX[TITTOT = 0.482 - (0.388PI/PIMAX), r = -0.53; p < 0.05]. These patients also had greater TTMUS (TTMUS = 0.087 +/- 0.030 in CF vs. 0.056 +/- 0.014 in controls, P < 0.01) that increased with decreasing lean body mass (r = -0.70, P < 0.005), with increasing percent predicted functional residual capacity (r = 0.70, P < 0.05), and increasing volumes of trapped gas (r = 0.77, P < 0.01). The multiple linear regression analysis for these factors was significant (R2 = 0.84, P < 0.01); however, the partial regression coefficient was significant only for lean body mass (r2 = 0.60, P < 0.05). Therefore, muscle mass appeared as the strongest determinant of TTMUS in CF. This study used a noninvasive method to assess the inspiratory muscle performance in children with CF. The results suggest impairment in inspiratory muscle function in these children despite good nutritional status and only mild to moderate alteration in pulmonary function tests. In addition, we were able to investigate some of the determinants of inspiratory muscle weakness, namely, muscle mass, hyperinflation, and trapped gas, and found that muscle mass played a predominant role.

[Cardiac adaptation to muscular exercise in children after complete repair of tetralogy of Fallot]. / Adaptation cardiaque à l'exercice musculaire chez l'enfant après réparation complète de tétralogie de Fallot.

The aim of this study was to assess cardiac adaptation to muscular exercise in children operated for tetralogy of Fallot. Eight children with a history of tetralogy of Fallot were studied and compared with ten control children. The basal evaluation consisted of an electrocardiogram, spirometry in all cases. Chest X-ray and echocardiography in all operated children. A muscular exercise stress test with incremental load on a bicycle ergometer was carried out with measurement of the cardiac output by CO2 rebreathing (experimental method). Under resting conditions, the two groups were comparable with respect to anthropometrical parameters and respiratory function. The cardiovascular data confirmed the good postoperative results of the children with a history of tetralogy of Fallot; cardiothoracic index of 0.49 to 0.55; sinus rhythm on the electrocardiogram; right ventricular pressures within normal limits; residual instantaneous right ventricular-pulmonary artery pressure gradient less than 25 mmH. On exercise, there was no significant difference with respect to VO2max, maximal heart rate, maximal cardiac output and maximal ventilation. The relationship between cardiac output and oxygen consumption was linear in two groups: y = 8.17x + 1.95 in the control group, y = 8.57x + 2.82 in the operated children. The change in cardiac output on exercise was comparable in the two groups. These observations seemed to be related to the good postoperative haemodynamic result: absence of pulmonary sequellae and right ventricular dysfunction. Despite the normality of the results obtained in this series, exercise stress testing with analysis of cardiac and respiratory adaptation would seem to be necessary in the follow-up of children operated for tetralogy of Fallot to exclude a ventilatory or circulatory limitation.

Familial non-syndromic conotruncal defects are not associated with a 22q11 microdeletion.

Molecular studies have shown microdeletions in region q11 of chromosome 22 in nearly all patients with DiGeorge, velocardiofacial and conotruncal anomaly face syndromes (DGS, VCFS and CTAFS, respectively) and in a high percentage of non-syndromic familial cases of conotruncal defects (CTD). CTD account for roughly a fourth to a third of all non-syndromic congenital heart defects (CHD), thus, 22q11 could harbor a major genetic factor of CHD. We searched for a 22q11 microdeletion in familial cases of non-syndromic CTD. Thirty-six cases of various isolated CTD, that is without history of hypocalcemia, immune deficiency, absent thymus, and dysmorphic appearance, were selected. With 48F8, a cosmid probe localized in the smallest deleted region of the DiGeorge critical region (DGCR), we found no deletions by fluorescence in situ hybridization in these 36 affected individuals of 16 families with recurrent CTD. Moreover, D22S264, a microsatellite localized at the distal part of the largest deleted region, was used to genotype the patients. Thirty-two patients out of 37 were heterozygous and hence not deleted at this locus, whereas 5 were uninformative. In conclusion, there are no large deletions in familial cases of various CTD, whether these defects are identical or not within a family. This result does not rule out other minor anomalies in this chromosomal region.