S4 and acute left sided valvular regurgitations
|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. Hence S4 does not occur in acute aortic regurgitation. Mitral valve pre-closure in acute aortic regurgitation is due to the high left ventricular end diastolic pressure.