Master the board step 3

Cardiology
Therefore, when you suspect valvular disease, select the cardiovascular, chest,
and extremities portion of the physical exam.
Murmurs
The most difficult important aspect for the exam is the part of the valvular heart
disease section that concerns understanding auscultation, particularly the effects
of various maneuvers on these murmurs. Systolic murmurs are most commonly
aortic stenosis, mitral regurgitation, mitral valve prolapse, and hypertrophic
obstructive cardiomyopathy (HOCM). Diastolic murmurs are most commonly
aortic regurgitation and mitral stenosis. All right-sided murmurs increase in
intensity with inhalation. All left-sided murmurs increase with exhalation.
Murmur intensity
increases with… Exhalation Inhalation
Side of murmur Left Right
Associated disease
Mitral and aortic valve
lesions
Both stenosis and
regurgitation of
tricuspid valves
Effects of Valsalva, Standing, Squatting, and Leg Raise
Maneuvers predominantly affect the volume of blood entering the heart.
Squatting and lifting the legs in the air increase venous return to the heart.
Valsalva maneuver and standing up suddenly decrease venous return to
the heart.
Valsalva maneuver is exhaling against a closed glottis, like bearing down
during a bowel movement or blowing against a thumb stuck in the mouth.
This increases intrathoracic pressure, which decreases blood return to
the heart.
When you suddenly squat, you are squeezing the veins of the legs, which are
rather large. This essentially squeezes blood up into the heart like squeezing
on a tube of toothpaste. For those too weak to squat suddenly, the physician
can lift up the legs. This has the same effect as squatting, which is to drain
blood into the chest from the lower extremities.
The majority of murmurs increase in intensity with squatting and leg raise.
Aortic stenosis (AS), aortic regurgitation (AR), mitral stenosis (MS), mitral
regurgitation (MR), and all right-sided heart lesions will become louder with
squatting and leg raising. The only two murmurs that become softer with
these maneuvers are mitral valve prolapse (MVP) and hypertrophic obstructive
cardiomyopathy (HOCM).
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