Flow murmur. Ejection systolic murmur usually refers to a benign murmur caused by increased blood flow. In other words, this is a functional murmur and not caused by any valvular pathology. Common causes are increased heart rate, increased adrenergic tone (ie adrenaline), increase blood volume as in a pregnant state. More serious systolic murmurs indicate aortic stenosis, or outflow tract obstruction.
Murmurs... An ejection systolic murmur is a murmur suring the systolic phase of the heart during the ejection through either the pulmonic or aortic valve (e.g. Aortic stenosis). This is different from a systolic murmur caused by regurgitation through one of the av valves.