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)
  
• In some cases as heard in our example, a high “cooing” diastolic murmur is heard, and this is associated with AR with the aortic cusps being folded backwards or retroverted.