Now we are going to learn a very important diastolic murmur. The heart sits in the chest like your fist and the aorta goes in this direction, so aortic stenosis, narrowing of the valve, the murmur goes up in this direction, but with aortic regurgitation, it goes down in this direction, so you hear the murmur of aortic regurgitation, it goes down in this direction, so you hear the murmur of aortic regurgitation best at the mid left sternal edge, the direction of flow. Let’s everybody listen together, timing of the carotid.
[sounds]
I used very firm pressure of the diaphragm on the chest wall in order to bring out this high frequency diastolic decrescendo murmur. It is high frequency because the leak is from the high pressure aorta into the lower pressure ventricular chamber in diastole, and you hear [sounds]. You do that [sounds]. Classic diastolic decrescendo murmur of aortic regurgitation and, by the way, significant aortic regurgitation is also reflected in the fact that the carotid vessel is bifid and rapid rising and the apical impulse is displaced and hyperdynamic. Aortic regurgitation [sounds].
Murmur Location and Radiation
The murmur is best heard at the lower left sternal edge, and this location is related to the underlying lesion. Note the position of the aortic valve in relationship to chest wall landmarks. Regurgitation from this valve results in turbulent diastolic flow in the direction of the mid-to-lower left sternal edge.
AR Heart Animation
This is a graphic example of the heart in a patient with aortic regurgitation. In the animation that follows, we can appreciate that the murmur is generated across the regurgitant aortic valve during left ventricular diastole.
AR Pressure Curves
These simultaneous aortic and left ventricular pressure curves illustrate the relationship of the hemodynamic events to the timing, contour and frequency of the murmur. The murmur begins with the aortic sound because the aortic root diastolic pressure exceeds left ventricular pressure immediately after the onset of diastole. The murmur then diminishes as aortic root pressure falls and left ventricular pressure rises in diastole. Because the pressure difference does not disappear, the murmur is long. The murmur is high frequency primarily because blood is flowing from the high pressure aortic root to the low pressure left ventricle. When pulmonary regurgitation is due to pulmonary hypertension, analogous events occur on the right side. [sounds]