Grading of Hill’s sign in aortic regurgitation
Hill’s sign is based on the difference between the upper limb and lower limb arterial pressures recorded by the sphygmomanometer. Sytsolic pressure recorded from the lower limb is more than that from the upper limb. Difference in systolic pressure above 20 mm Hg is taken as significant. When Hill’s sign is taken for grading the severity of aortic regurgitation, the following classification is usually applied:
Mild AR: 20 – 40 mm Hg
Moderate AR: 40 – 60 mm Hg
Severe AR: More than 60 mm Hg
S4 and acute left sided valvular regurgitations
S4 is never heard in acute aortic regurgitation while it is heard in acute mitral regurgitation. Mitral valve pre-closure occurs in acute aortic regurgitation.
S3 and left ventricular dysfunction
S3 can occur in mitral regurgitation without left ventricular dysfunction while presence of S3 in aortic regurgitation indicates left ventricular dysfunction.