The murmur of aortic regurgitation is best heard with the diaphragm of the stethoscope. Low-intensity, high-pitched aortic regurgitation murmurs may not be heard unless firm pressure is applied with the diaphragm of the stethoscope over the left sternal border or over the right second interspace, while the patient sits and leans forward with the breath held in full expiration.
The radiation of an aortic regurgitation murmur is toward the cardiac apex and the location of maximum intensity may vary considerably. It can be best heard in some patients over the mid precordium, along the lower left sternal border, or even over the cardiac apex (movie 10). Radiation of the murmur to the right sternal border is more common in aortic regurgitation caused by aortic root or aortic cusp anomalies [26].
The configuration of the aortic regurgitation murmur is usually decrescendo because the magnitude of regurgitation progressively declines. The murmur is high-frequency and has a “blowing” character. Occasionally the murmur can be musical in quality (diastolic whoop); this has been attributed to a flail everted aortic cusp. The “whoop” can be mid-, late-, or pandiastolic [27].
The duration of the murmur is variable but usually terminates before S1. The duration of the murmur does not always correlate with the severity of aortic regurgitation, although mild aortic regurgitation is usually associated with a murmur of brief duration. The murmur may also be short with acute severe aortic regurgitation because of a rapid increase in LV diastolic pressure, which equalizes with aortic diastolic pressure soon after the onset of diastole. If the aortic pressure remains higher than LV pressure throughout diastole, a pandiastolic murmur may be present, even when the severity of aortic regurgitation is only moderate. Bedside evaluation of the severity of aortic regurgitation should be primarily based upon a determination of the hemodynamic consequences. Thank you.