Does the loudness of the murmur reflect the severity of the aortic stenosis ?
No, the loudness of the murmur is related more to the cardiac output and the systolic turbulence
surrounding the valve than to the severity of the stenosis. Thus, a loud murmur may be associated with
trivial stenosis and, in severe heart failure, the mur-mur may be soft because of decreased flow across
the valve from the diminished cardiac output.