[Physiological and paraphysiological echocardiographic findings in neonatal and pediatric age].

Echocardiographic quantification is crucial for the diagnosis and management of patients with acquired and congenital heart disease (CHD). In neonatal and pediatric age, the echocardiogram begins with subxiphoid, or subcostal, imaging instead of left parasternal views. This allows for the determination of visceral situs (site or location) at the beginning of an examination. Regardless of where the examination starts, the segmental approach is used to describe all of the major cardiovascular structures in sequence. Patent foramen ovale is a normal interatrial communication during fetal life. Complete anatomic closure of the foramen ovale occurs in 70-75% of adults, which means that almost 25% of the population has a patent foramen ovale. Atrial septal defects are a common congenital disorder with a prevalence of approximately 2 per 1000 live births. The reported rate of spontaneous atrial septal defect closure in the first year of life ranges from 4% to 96%. The most important predictor for spontaneous closure is the size of the defect, with smaller defects more likely to close. Systemic-to-pulmonary collateral arteries can occur in premature infants without chronic lung disease and may represent a transient phenomenon. They may be present normally after birth and then gradually disappear. Physiological valvular regurgitation is most commonly observed in the tricuspid valve among children (32.8%), followed by pulmonary regurgitation (17.2%). The ductus arteriosus usually is functionally closed within 48 h of birth, although some authors consider the patent ductus to be abnormal only after 3 months of age. Prematurity clearly increases the incidence of patent ductus arteriosus.