systolic murmurs

Systolic heart murmurs are heart murmurs heard during systole, i.e. they begin and end between S1 and S2. Many involve stenosis of the semilunar valves or regurgitation of the atrioventricular valves.

Mid-systolic ejection murmurs are due to blood flow through the semilunar valves. They occur at the start of blood ejection — which starts after S1 — and ends with the cessation of the blood flow — which is before S2. Therefore, the onset of a midsystolic ejection murmur is separated from S1 by the ...