The
Murmur
AR is a good example of the importance of auscultation: Given that
patients are often asymptomatic and diastolic pressure does not
necessarily indicate hypertension, the state is often overlooked. Chronic
AR will over time develop a non-reversible ventricular failure and early
detection of a diastolic murmur is often the first clue to this process.
Treated early, the serious results of a dilated ventricle may be
prevented.
In
Aortic Regurgitation the backflow of blood across the aortic valve will
cause a holodiastolic murmur. It is often described as a relatively
high-pitched murmur of blowing character. The murmur may be loud or soft
depending on the severity of the regurgitation. Remember, soft murmurs
indicate a larger regurgitant flow than a loud murmur! So soft is worse
than loud, contrary to what is the case with stenotic valves where the
opposite is the case.
- In
moderate AR, a relatively loud early desending diastolic murmur is heard.
- With
more severe AR, the murmur becomes longer, and will usually decrease
in intensity.
- The
classic murmur caused by the regurgitant flow is best heard along the
lower left sternal border. In some cases (Marfan’s Syndrome, VSD
w/AR , aortic dissection or aneurysm) it is best heard at the right
sternal border.
- If,
in addition, a lower-pitched mid-diastolic murmur is heard over apex
this indicates what is called an Austin Flint murmur which indicates
severe AR. (The murmur is not the regurgitatant flow over the aortic
valve, but rather vibrations in a restricted Mitral Valve when the
left atrium empties and is met with the opposite flow from the aortic
valve)
- In
addition to the diastolic murmur(s), a systolic flow murmur like in
aortic stenosis may be heard. This is not necessarily indicating a
calcified valve, as the increased velocity resulting from ventricular
overload will also cause flow vibrations).
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