Sports and congenital cardiopathies]

The authors give recommendations regarding the eligibility to sport practice of children with cardiovascular abnormalities. Exercise testing is important to determine the consequences of the cardiovascular abnormality on the child's physical ability. Echocardiography with Doppler ultrasound is essential in order to assess the repercussion of valvulopathies, particularly on the function of the left ventricle. Holter electrocardiographic recording is useful in the case of a history of malaises or syncopes. These investigations allow those children who are at risk of cardiac accidents during sport practice to be recognised, and to choose the sport which is the most appropriate to their individual condition. There are few complete contra indications to all types of sports, essentially obstructive myocardiopathy, primary pulmonary hypertension, severe aortic stenosis, and coronary abnormality.     

Complete surgical correction of congenital cardiopathies in infants]

The results of total correction of congenital heart defects in the first year of life are presented. Overall surgical mortality in these generally highly symptomatic infants was 35%. The surgical risk is mainly related to the type of defect: mortality is low (10%) in uncomplicated septal defects and in transpositions of the great vessels, higher in the coarctation syndromes (30%), and considerable in complex heart defects. The weight of the infant seems to be another factor, surgical mortality being high when the patient's weight is less than 4.5 kg. Indications for palliative operation or total repair are discussed on the basis of the presented results.     

Genetics of congenital dwarfism

Eighty two cases of dwarfism of genetic etiology are described of 1100 cases referred to a specialised genetic clinic over 2 years. Short limb dwarfism (33 cases) formed the maximum number followed by chromosomal anomalies (25 cases). Eleven cases of genetic syndromes and 12 cases with metabolic disorders had short stature.     

Genetics of congenital dwarfism

Eighty two cases of dwarfism of genetic etiology are described of 1100 cases referred to a specialised genetic clinic over 2 years. Short limb dwarfism (33 cases) formed the maximum number followed by chromosomal anomalies (25 cases). Eleven cases of genetic syndromes and 12 cases with metabolic disorders had short stature.     

Epidemiological and genetic study of 3 congenital cardiopathies with neonatal disclosure

A familial study was undertaken on 382 probands with transposition of the great vessels, 348 with coarctation of the aorta and 143 with hypoplastic left heart syndrome. It allowed to assess in sibs the frequency of identical congenital heart diseases (respectively 0.15, 0.42 and 3.41%) and of all 7.32%). The epidemiological study did not provide further data worth noting. At the origin of the transposition of the great vessels, tetratogenetic factors are added to genetic factors, whose part is of little importance; hypoplastic left heart syndromes are heterogeneous (recessive autosomal transmission, chromosome abnormalities, sporadic cases). Coarctations of the aorta, which are dependent on different mechanisms are also heterogeneous. It is possible that common factors, whether hereditary or not, play a part on one hand in hypoplastic left heart syndromes and coarctations of the aorta, and, on the other hand, in some congenital heart diseases.     

Genetics of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a common structural birth defect that affects approximately 1 in 2500 live births. Although the exact etiology of most cases of CDH remains unknown, it is becoming increasingly clear that genetic factors play an important role in many cases of CDH. In this paper, we review critical findings in the areas of clinical and basic research that highlight the importance of genetics in the development of CDH. We also provide practical information that can aid physicians and surgeons as they evaluate and care for patients with isolated, nonisolated, and syndromic forms of CDH and their families.     

Genetics of congenital hyperinsulinemic hypoglycemia

A genetic diagnosis is now possible for approximately 45%-55% of patients with hyperinsulinemic hypoglycemia. Understanding the genetic etiology of the disease in these patients is clinically important because a genetic diagnosis will provide information on prognosis, recurrence risk, and importantly may also guide clinical management. The aim of this review is to provide an outline of the 7 different molecular mechanisms underlying this heterogeneous disease and to demonstrate that the clinical phenotype can act as a useful guide when prioritizing the order of genetic testing.     

Genetics of congenital heart diseases]

New insights into the genetics of congenital heart diseases in human beings have been drawn these past years. The identification of genes for heart defects have led to a new clinical approach of these malformations in children and their families. These progresses have been made with the help of positional cloning as well as with the analysis of mouse models. These findings also yielded a new complexity in understanding the development of cardiac defects and led to revise the different classifications for congenital heart defects. Pediatric cardiologists have also improved their efficiency in defining cardiac phenotypes in affected individuals and in pedigrees with recurrent malformations. Genetic heterogeneity has made the molecular approach of a given defect difficult. In addition, intrafamilial variability still has scarce explanations. Finally, the contribution of epigenetic factors has to be kept in mind in specific conditions such as twin gestations. Clinical consequences of these findings remain at the present time limited for the patients themselves but in particular cases, genetic counseling has been dramatically improved.     

Ventilation in special situations. Mechanical ventilation in congenital cardiopathies and pulmonary hypertension

The cardiovascular and respiratory systems act as a functional unit. Mechanical ventilation modifies pulmonary volumes, which generates changes in autonomic nervous system reactivity and provokes tachy- or brady-cardia (depending on the tidal volume used). Mechanical ventilation also decreases cardiac filling volumes (pre-load) and alters pulmonary vascular resistances. In addition, intrathoracic pressures are enlarged, which usually produces a decrease in right atrium filling and an increase in right ventricle afterload. If coronary flow is impaired, myocardial contractility is reduced. However, if cardiac failure is present, mechanical ventilation is especially beneficial because it corrects hypoxia and respiratory acidosis, decreases the work of breathing, and improves stroke volume. Mechanical ventilation in congenital heart diseases is indicated either as lifesaving support or as physiopathological treatment to modify the ratio between pulmonary and systemic flow. As a general rule, if excessive pulmonary blood flow is present, the aim of respiratory support is to increase pulmonary vascular resistance by using high levels of airway pressure and even by delivering FiO2<21%. When there is low pulmonary flow, the lowest possible intrathoracic pressures should be used, especially in cases of pulmonary hypertension, which will also require high FiO2. However, mechanical ventilation has adverse effects and consequently it must be stopped as early as possible, once the child is stable and requires minimal cardiopulmonary support. Weaning can even be performed in the operating room, when the surgical procedure is finished. When this is not possible, weaning should be performed in the pediatric intensive care unit. Because there are no criteria for successful withdrawal of mechanical support in congenital heart disease, general pediatric criteria should be used.     

Contribution of magnetic resonance imaging in the neonatal diagnosis of congenital cardiopathies. Apropos of 10 cases

The aim of this study was to evaluate potential indications of Magnetic Resonance Imaging (MRI) in the diagnostic workup of congenital heart disease in the newborn in comparison with two other means of investigation: Doppler-echocardiography and angiography. The imaging permitted to make the diagnosis in the 10 cases. MRI was superior than echocardiography in one newborn with a double aortic arch. MRI detected small muscular ventricular septum defects in two newborns with transposition of the great vessels. There was good agreement between MRI and angiographic images. Neither age nor prematurity proved to pose a limit on the diagnosis of MRI. MRI proved to be a good investigative tool which should be used after echocardiography, eventually making it possible to avoid angiography.