What is a possible cause of a 3rd heart sound in children?

A third heart sound, often referred to as S3, can indeed be a normal finding in children. In pediatrics, the presence of an S3 heart sound typically indicates rapid ventricular filling during early diastole, which is a common and expected occurrence due to the high compliance of the ventricular walls. This can be attributed to the physiological differences in children's heart structure and function compared to adults, where an S3 could indicate more serious conditions like heart failure.

In healthy children, the S3 sound indicates that the heart is functioning optimally, with no underlying pathology affecting its ability to manage blood flow. This sound becomes less common as one ages, as changes in heart structure and function occur, causing the sound to typically be associated with pathological states in adults. Therefore, when evaluating heart sounds in children, an S3 can be a sign of a healthy heart rather than an indication of disease.

Understanding this nuance is important for clinicians in order to accurately assess pediatric patients.