Which heart murmur is often considered innocent in children?

Still's murmur is characterized as an innocent or functional heart murmur that is commonly observed in children. It is typically a result of heightened blood flow across the valves due to rapid growth or certain hemodynamic changes during childhood.

This murmur is usually low in pitch and has a musical quality, often best heard when the child is lying down or in a sitting position. It is generally not associated with any pathological heart conditions, meaning it does not indicate any underlying heart disease or abnormalities. In most cases, Still's murmur will resolve as the child grows and their circulatory system matures.

The other murmurs mentioned represent pathological conditions that can lead to heart issues. Mitral regurgitation, for instance, indicates that the heart’s mitral valve is not closing properly, potentially leading to complications. Aortic stenosis is a narrowing of the aortic valve that can obstruct blood flow from the heart, leading to significant issues if severe. Patent ductus arteriosus involves a persistent connection between the aorta and pulmonary artery after birth, which can lead to heart failure if not addressed.

Thus, Still's murmur stands out as a benign finding in pediatric examinations, whereas the others point to conditions that may require further evaluation and management