a u s c u l t a t i o n    t u t o r
Aortic Stenosis

The murmur of aortic stenosis is typically a mid-systolic ejection murmur,
heard best over the “aortic area” or right second intercostal space, with
radiation into the right neck. This radiation is such a sensitive finding that
its absence should cause the physician to question the diagnosis of aortic
stenosis. It has a harsh quality and may be associated with a palpably slow
rise of the carotid upstroke. Additional heart sounds, such as an S4, may
be heard secondary to hypertrophy of the left ventricle which is caused by
the greatly increased work required to pump blood through the stenotic
valve. Because the second heart sound is largely generated by the
sudden closing of the aortic valve, a poorly mobile and stenotic aortic
valve may cause S2 to become quieter or even absent. Although S2 is
normally created by the closure of the aortic valve followed by the
pulmonary valve, if the closure of the aortic valve is delayed enough, it
may close after the pulmonary, creating an abnormal paradoxical
splitting of S2.

 Aortic stenosis is a progressive disease, with typical symptoms and
clinical findings to match its course. A good mnemonic to remember the
march of symptoms related to undiagnosed aortic stenosis is ASC, or
Aortic Stenosis Complications. One of the early symptoms is Angina,
which is usually stable and exertion-related. A more serious and later
condition is Syncope, again associated with exercise. Finally, the
hypertrophied left ventricle can no longer meet demands, and Congestive
heart failure may ensue. On examination, the phase during systole at
which the murmur peaks can help to determine the severity of the disease.
An early-peaking murmur is usually associated with a less stenotic valve,
while a late-peaking murmur has a more severe degree of stenosis. This is
because a more stenotic valve takes longer for the ventricle to generate
the terrific pressures needed to force the blood past the lesion.
t h e     h e a r t
Normal Cardiac Cycle
You need Java to see this applet.
Mississauga ON     [GMT -6hrs]      info@davidklein.org     c 647 300 8110