What percentage of children with Down syndrome have congenital heart disease?
Approximately 40%-50% of children with Down syndrome are born with congenital heart disease.
– What are the causes?
Congenital heart disease is generally considered to have a multifactorial origin, combining genetic and probably environmental causes. Parents who have had a child with a heart disease, as well as the child himself, will have a higher risk of their offspring also suffering from congenital heart disease in later life. This supports the genetic hypothesis as a strong conditioning factor in the appearance of these pathologies.
However, at present it is still not known exactly what causes a child to develop a specific heart disease. In the case of Down syndrome, trisomy of chromosome 21 is considered to be responsible for the medical problems affecting these patients, including heart defects. In the near future, it is very likely that the field of genetics, now in full expansion, will provide us with answers to these questions.
– What are the most common cardiac problems?
Although any congenital heart disease can appear in children with Down syndrome, the most frequent are ventricular septal defect, atrial septal defect and complete or incomplete atrioventricular canal.
In addition, to a lesser extent we find patent ductus, tetralogy of Fallot or coarctation of the aorta. Moreover, these heart diseases can appear isolated or combined, some of them in the same child.
– How are these cardiac anomalies detected?
Depending on the type of heart disease in question, these defects can be detected in utero by fetal echocardiography, or postnatally due to the appearance of clinical signs or symptoms of heart disease in the child. In the fetal period, complete or incomplete atrioventricular canal, tetralogy of Fallot and even coarctation of the aorta and moderate or large ventricular septal defect are susceptible to detection.
In the postnatal phase, if these defects have not been detected in the fetal period, they will be diagnosed in the first days of life, since they have a high clinical expression in the infant.
In the case of less serious defects, such as atrial septal defect or patent ductus, they may not even cause symptoms or clinical signs of heart disease in the first weeks of life, and are only detectable by routine cardiological study.
For this reason, any child with Down syndrome should be studied cardiologically in the first days of life, even if the clinical examination does not suggest cardiac pathology.
– What does the treatment consist of?
Some of the typical heart diseases in children with Down syndrome are always surgical, such as complete and incomplete canal, coarctation of the aorta and tetralogy of Fallot.
The optimal time for surgery differs from one to another, although it should generally be performed in the first days or months of life, with the exception of incomplete canal, whose correction is usually delayed until the first or second year of life.
In the case of ventricular or atrial septal defects, surgical closure of the defect is only necessary if the defect is large and, above all, if it causes clinical symptoms in the young infant, such as poor weight curve, frequent respiratory infections or pulmonary hypertension.
Some atrial septal defects and patent ductus arteriosus, and to a lesser extent, ventricular septal defects, if they are of moderate size and have few or no symptoms, can be closed by interventional catheterization after the first months of infancy or in the first years of life. Finally, some small defects may not require invasive procedures of any kind, as they do not cause symptoms in the child, and only require periodic check-ups every several months or even several years.