Flashcards in 12.6 B Deck (31):
What is a holo or pan murmur?
one with relatively constant loudness
Which mitral and aortic valve related murmurs are systolic?
mitral regurgitation and aortic stenosis
Which mitral and aortic valve related murmurs are diastolic?
aortic regurgitation and mitral stenosis
The intensity of a murmur is directly related to ___ which is directly related to ___.
- the magnitude of flow across the defective valve
- the pressure gradient across the valve during flow
LV afterload is ___ and TPR is ___ in someone with aortic stenosis.
- afterload is increased
- TPR is unchanged
What happens to the pressure gradient between the aorta and left ventricle during systole in someone with aortic stenosis?
- the pressure gradient is zero at the time of valve opening by definition
- but then the ventricle continues to contract without a corresponding amount of flow into the aorta, increasing ventricle pressure without increasing aortic pressure
- the gradient increases and then falls
Describe an aortic stenosis murmur.
What happens to arterial pulse pressure in someone with aortic stenosis?
- it is diminished
- because flow into the aorta is slowed, systolic arterial pressure never gets as high as it otherwise would
- systole also takes longer so there is less time for diastole and thus less time for runoff, increasing diastolic arterial pressure
What happens to diastolic arterial pressure in someone with aortic stenosis?
it is increased because systole takes longer and there is less time for runoff
What chronic changes are seen in someone with aortic stenosis?
- left ventricular hypertrophy
- left atrial hypertrophy since LV hypertrophy will decrease compliance of the LV
What effect does aortic stenosis have on exercise?
it greatly restricts the bodies attempts to increase cardiac output and individuals may faint during exercise
Which chambers are likely to hypertrophy in someone with aortic stenosis?
- LV because it's working against more valvular resistance
- LA because LV hypertrophy limits compliance
Describe an aortic insufficiency murmur.
a diastolic decrescendo murmur
Why is an aortic insufficiency murmur a decrescendo?
because as the left ventricle fills during diastole and the aorta loses blood to the ventricle, the pressure difference between the two is diminished
What happens to arterial diastolic pressure in someone with aortic insufficiency?
it will greatly decrease because there is now an additional route for runoff
What happens to arterial pulse pressure in someone with aortic insufficiency?
- systolic pressure increased due to increased SV
- diastolic pressure decreased due to additional route for runoff
How does LV hypertrophy so often lead to LA hypertrophy?
the LV hypertrophy diminishes compliance, so the LA must compensate
How does LV hypertrophy lead to pulmonary edema?
LV hypertrophy causes an increase in EDP, which increases pressure back upstream, including in pulmonary capillaries
Describe the murmur associated with mitral valve insufficiency.
a holo/pan systolic murmur
Why is a mitral valve insufficiency murmur a pan murmur?
because as the LV contracts and the pressure rises, blood flows back into the LA where pressure also rises, thus the pressure gradient remains roughly constant
Which chambers hypertrophy in mitral valve insufficiency?
- LA due to increased volume with return from LV
- LV due to increased volume due to increased LA filling
Which valve will never hypertrophy in mitral valve stenosis?
the left ventricle because it will constantly struggle to fill
Describe a mitral valve stenosis murmur.
a diastolic decrescendo-crescendo
Why is the mitral valve stenosis murmur a decrescendo-crescendo?
- initially, the ventricle fills as the atrium empties passively and the pressures converge
- towards the end of diastole, though, the atrium contracts and there is an increase in atrial pressure that is greater than the increase in ventricular pressure due to resistance to flow and the pressure gradient increases
Which valves are expected to hypertrophy in someone with mitral valve stenosis?
Why would the right ventricle hypertrophy in mitral valve stenosis?
- high left atrial pressure increases pressure in pulmonary veins
- this causes edema in the pulmonary veins which leads to hypoxia
- hypoxia triggers vasoconstriction
- vasoconstriction increases pulmonary artery pressure
- the right ventricle has a greater afterload
How does mitral valve stenosis show up on an EKG?
- LA hypertrophy creates a notched P wave
- RV hypertrophy causes a right axis shift
Aortic stenosis has what effect on S2?
Pulmonic stenosis has what effect on S2?
Left heart murmurs get louder during (inspiration/expiration).