Congenital heart disease

The term congenital heart disease is used to describe disorders of the heart and great vessels that originate before birth. Most of these processes are due to defective development of the embryo during pregnancy, when the main cardiovascular structures are formed. The most serious alterations may be incompatible with intrauterine life, but there are many that become evident only after birth. Worldwide, it is estimated that between 8 and 10 cases occur per 1,000 births.

The medicine of the 21st century has the technology to detect the majority of these congenital malformations before birth, although they still with certain limitations.

Introduction

The terms congenital and hereditary are not synonyms: all hereditary diseases are congenital, but not all congenital diseases are hereditary.

Some produce manifestations shortly after birth, often related to the transition from fetal to postnatal circulation (with oxygenation dependent on the lungs, and not the placenta). Others, however, do not manifest until adulthood (eg, coarctation of the aorta or atrial septal defect (ASD)).

The most common heart diseases are ventricular septal defect (VSD) with 18-20% of the total, atrial septal defect (ASD) with 5-8% and patent ductus arteriosus (PCA) with 5-10%. These are called acyanotic heart diseases because they do not produce cyanosis or bluish color of the skin and are associated with increased pulmonary flow, heart failure, malnutrition and repeated respiratory infections. Among cyanotic congenital heart diseases, the most common is tetralogy of Fallot (TF), which is responsible for between 5 and 10% of all heart defects.

Remarkable advances have been made in the diagnosis and treatment of congenital heart diseases, which have allowed the lives of many children to be prolonged. Most of them are susceptible to surgical repair which is followed by good results.

Etiology

The cause of congenital heart disease can be genetic or some environmental alteration that influences the development of organs, among the latter we can mention infection by the rubella virus during pregnancy, alcohol consumption by the mother, maternal diabetes and certain drugs taken during pregnancy such as hydantoin, lithium salts and thalidomide. In many cases, the cause that caused the problem is not detected.

Classification

• Congenital heart chamber malformations and their connections
  • Transposition of large vessels
  • Truncus arteriosus persistent
• Heart septal malformations
  • Interauricular communication
  • Interventricular communication
  • Tetralogy of Fallot
• Pulmonary and tricuspid valve malformations
  • Pulmonary
  • Atresia tricuspídea
  • Anomaly of Ebstein
• Aortic and mitral valve malformations
• Other congenital heart malformations
  • Dextrocardia
• Congenital malformations of the great arteries
  • Aorta coartation
  • Persistent artery Ductus
  • Origin left coronary anomaly in the pulmonary artery
• Congenital malformations of the great veins
  • Cymitage Syndrome

• Other congenital malformations of the circulatory system

Associated diseases

Most congenital heart diseases have no other associated defects, but there are chromosomal and genetic syndromes in which congenital heart disease is a part of a more complex disorder. Among these we find:

• Down syndrome: Between 40 to 50 % of children have heart disease, among them we have; interventricular communication, interauricular communication, persistent arteriosus ductus and Fallot tetralogy.
• Marfan syndrome: Mitral valve prolapse, aortic dissection, aortic aneurysm.
• Turner syndrome: Aorta coartation, bicuspid aortic valve, persistent artery ductus, pulmonary valve stenosis.
• Patau syndrome (trisomia 13): Dextrocardia, interventricular communication, interauricular communication, persistent arteriosus duct.
• Noonan syndrome: Between 50% and 80% of patients have heart disease, among them they are; pulmonary valve stenosis with valve dysplasia, mipertrophic myocardiopatia and less frequent interauricular communication, interventricular communication, pulmonary stenosis, Fallot tetralogy and aortic coartation.
• DiGeorge syndrome: Aortic coartation, Fallot tetralogy.

General clinical picture

Symptoms depend on the specific condition. They may not be obvious at birth, some disorders such as coarctation of the aorta may not cause problems for many years. People with a small ventricular septal defect (VSD) may not have any symptoms and have normal physical activity. Some of the most important symptoms are:

• Persistent Cianosis aggravated by effort.
• Heart murmur, according to the present defect.
• Sincopes.
• Congestive heart failure.
• He tired with effort (when he cries, sucks and shakes).
• Decrease in blood oxygen levels.

When there is a left-right shunt, the main symptoms are lung infections, pulmonary hypertension and Eisenmenger syndrome. On the other hand, if there is a right-left shunt, polyglobulia and hypoxia crises predominate.

Frequency by sex

Some congenital heart diseases are more common in men, while others are more common in women. Among these defects we have patent ductus arteriosus (1 ♂♂: 2.72 ♀♀), Lutembacher disease (1 ♂♂: 2.1 ♀♀), and ostium secundum (1 ♂♂: 1.84 ♀♀).

The most common congenital heart diseases in men are: aortic stenosis (2.66 ♂♂: 1♀♀), coarctation of the aorta (2.14 ♂♂: 1 ♀♀), transposition of the great arteries (1.90 ♂♂: 1 ♀♀), a total anomalous connection of pulmonary veins (1.39 ♂♂: 1 ♀♀), and coarctation of aorta with an open arterial canal (1.37 ♂♂: 1 ♀♀).

Other congenital heart defects occur with approximately the same frequency in both sexes. Among them ostium primum, partial and total atrioventricular septal defect, Ebstein's anomaly and tricuspid atresia.

Theories about the origin of congenital heart diseases

Rokitansky (1875) explained congenital heart defects as interruptions in the development of the heart at various stages of ontogeny. Spitzer (1923) treated them as a return to an earlier stage of phylogenesis. Krimsky (1963) synthesizes the two previous points of view and considers congenital heart diseases as an interruption of the development of the organ in a certain phase of ontogenesis, which corresponds to a stage of phylogenesis, that is, a previous period of the evolutionary process.