Aortic Regurgitation Aortic Regurgitation Aortic regurgitation occurs if the aortic valves become incompetent. An incompetent aortic valve does not have the structural integrity to hold the high pressure that occurs after the aortic valve closes. This occurs during diastole, between the S2 and S1 heart sounds.
Aortic regurgitation causes a decrescendo murmur that is an early diastolic murmur.
This occurs because as the force of the left ventricle decreases and the aortic valve shuts, the valve is unable to hold back the high pressure against the valve leaflets. As high pressure develops in the aortic arch after the closure of the aortic valve, the fluid force against the Aortic valve and in the Aortic Arch becomes high enough to force opened the aortic valve leaflets. This leads to a backward flow of blood into the left ventricle. Then later in diastole, as blood flows systemically through the arterial system, the pressure in the aortic arch decreases, and as the pressure against the aortic valve decreases. Please lessen to the sound file on decrescendo aortic regurgitation.