Murmur	Description	Proposed etiology	Common age prevalence	Audio
Still’s murmur	Systolic Grade 1 to 2 Low frequency, such as a twanging string, musical Heard between sternal border (mid to lower position) and apex Most common murmur in children	Unknown, theories include resonant phenomena of blood movement into the aorta, or movement across a chordae tendinae	3 to 6 years, should disappear by adolescence	Audio file
Pulmonary ejection/flow murmur	Systolic Slightly grading in contrast to vibratory Heard over left upper sternal border, no significant radiation	Exaggeration of normal ejection vibration within the pulmonary vasculature	5 to 14 years, most common in adolescents	Audio file
Venous hum	Continuous, diastolic portion subtly louder Grade 1 to 2 Best heard infraclavicular and supraclavicular Only audible when patient is upright Can dissipate or exacerbate by head movements or obstruction of the ipsilateral jugular veins	Vibration of the veins carrying the blood from the head and upper body to the superior vena cava	3 to 6 years	Audio file