What is the most common innocent murmur found in newborns?

The most common innocent murmur found in newborns is the systolic ejection murmur. This type of murmur is typically soft, short in duration, and occurs during the phase of the heartbeat when blood is ejected from the ventricles into the great arteries (the aorta and pulmonary artery).

In the context of newborns, systolic ejection murmurs are often associated with the normal flow of blood through the heart and vessels and do not indicate any underlying heart disease. They result from increased blood flow across the valves, particularly the aortic and pulmonary valves, which can be more pronounced in newborns due to their heightened cardiac output and favorable hemodynamic conditions as they transition to life outside the womb.

Unlike diastolic murmurs, which occur during the heart's relaxation phase and can signify abnormal conditions, or continuous murmurs that typically indicate issues such as a patent ductus arteriosus, the systolic ejection murmur is a benign and common finding in otherwise healthy infants. Holosystolic murmurs, on the other hand, are also indicative of potential pathologies, often related to valvular insufficiencies.

Understanding the characteristics of these murmurs and recognizing that a systolic ejection murmur is generally