What can cause abnormalities indicated by ejection clicks in newborns?

Ejection clicks are specific heart sounds characterized by a high frequency and are often associated with the movement of the heart valves—primarily the aortic and pulmonic valves—during early systole. These sounds are typically produced when there is a rapid ejection of blood through a narrowed outflow tract. In newborns, abnormalities such as aortic stenosis can lead to the presence of ejection clicks due to the increased pressure required to propel blood through the narrowed aortic valve.

Aortic stenosis is a congenital heart defect where the aortic valve is either malformed or too narrow, which impedes blood flow from the heart into the aorta. This condition results in increased workload on the left ventricle and can produce the characteristic ejection click heard during auscultation.

While conditions like respiratory distress, nasal congestion, and atrial septal defect may impact a newborn's overall condition and could lead to various sounds or symptoms, they do not specifically result in ejection clicks. Therefore, the relationship between ejection clicks and aortic stenosis makes it the correct answer regarding the cause of these abnormalities in newborns.