Murmurs and Myocardial
Sounds…Making Sense of
the Madness
Sara G. Tariq, M.D.
August, 2012
Goals

Know how we classify murmurs
• Systolic

Crescendo-decrescendo
• Aortic stenosis, pulmonic stenosis, or “innocent”
murmur

Holosystolic
• Mitral regurg, tricuspid regurg or VSD

Late Systolic - MVP
• Diastolic

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Aortic regurgitation, pulmonic regurgitation
Stenosis of mitral or tricuspid
• Both

Patent Ductus Arteriosus
Goals


Know the significance of rubs
Know the significance of extra
sounds
• Split S2 (varies vs split)
• S3
• S4
What are murmurs?
Sounds
Murmurs exist because of turbulent
blood flow or increased velocity of
blood flow across an orifice (a
valve)
Usually 3 different kinds of sounds



•
Holosystolic, crescendo-decrescendo
or decrescendo,
Does sound matter?


Most murmurs will worsen with smaller
orifice size—so a very large VSD may have
almost no pressure gradient across its
mouth and thus little murmur but very
large physiologic consequences.
Conversely, a small VSD may have a very
turbulent jet with high velocity and a high
pressure gradient across its mouth and be
associated with a loud murmur, but have
a much lower hemodynamic significance.
Grading the Sound
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I-faintest murmur that can be heard (with
difficulty)
II- murmur is also a faint murmur but can
be identified immediately
III- moderately loud
IV- loud with a palpable thrill
V- very loud, but still need stethoscope
VI- loudest and can be heard without
stethoscope
S1 and S2

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Closing of the mitral (tricuspid, too)
and aortic (pulmonic, too) valves
Usually very crisp
You should hear S1 loudest at mitral
area
You should hear S2 loudest at aortic
area
Where do you hear murmurs?
• RUSB= (may radiate to neck)
• LUSB=Pulmonic (may radiate to back)
• LLSB=Tricuspid (usually doesn’t radiate)
• Apex=Mitral (may radiate to axilla)
Systolic murmurs
“swooshing” sounds
Occur right after S1 (closing of mitral
valve) and before S2 (closing aortic v)
Causes:



•
•
•
having trouble getting out of the ventricle
through a tight door (aortic stenosis)
You fall out through a door which should be
closed tight but isn’t (mitral reg)
A hole exists where it shouldn’t in the
ventricular septum and blood crosses from
high pressure side to low pressure side
(VSD)
Mitral regurgitation
Mitral regurgitation



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Mitral valve is incompetent and does
not close properly (door won’t close)
Result: abnormal leaking of blood
from the LV, through the mitral
valve, and into the left atrium
Causes: myxomatous degeneration,
MI, dilated LV
Sound: holosystolic (swoosh lasts
throughout systole) radiates to axilla
Mitral and tricuspid valves – like a
parachute
Systolic Murmurs

Mitral Regurgitation (apex)
• Systolic murmur
• Radiates to axilla
S1
S2
S1
Mitral valve prolapse


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displacement of an
abnormally thickened
mitral valve leaflet
that gets displaced
into the atrium in
systole
Mid-systolic click with
late systolic murmur
You can get mitral
regurg if severe
Aortic Stenosis
Aortic stenosis

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The aortic valve narrows
Creates turbulent blood flow across the
narrowed valve
Result- the heart has to work hard by
creating pressure to get blood across the
stenotic valve
Causes: congenitally bicuspid valve, wear
and tear from age, Rheumatic fever
Sound: crescendo-decrescendo murmur in
systole, radiates to carotids
Physical Exam: Cardiac

RUSB with diaphragm; radiates to
carotids bilaterally
S1
S2
S1
VSD
VSD

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Congenital – hole in septum
Left heart pressures>right heart
So in systole, when heart contracts,
the blood in the left goes across the
“window” into the right side
Holosystolic murmur, just like mitral
regurgitation
Only difference is that it is usually
over the sternal border

Systolic
• Ventricular Septal Defect

Continuous
• Arteriovenous connections (PDA)
“Innocent murmur”
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AKA “physiologic murmur”
Doesn’t radiate
Occurs NOT from a structural
problem in the heart but from
something outside the heart
Hyperthyroidism, anemia
Systolic Murmurs

Innocent murmurs
• Usually ‘diamond shaped’, brief, little
radiation
• Common in children and young adults
• ALWAYS: systolic, < III/VI intensity,
other heart sounds and pulses are
normal
S1
S2
S1
Diastolic murmurs= really bad

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Same “swoosh” but at a different
time
You hear it right after S2 and before
S1
Blood is having trouble leaving the
atrium to the ventricle b/c door is
partly shut (mitral stenosis)
Ventricular outflow tract can not stay
shut (aortic regurg)
Aortic Regurgitation
Aortic regurg

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Aortic valve can not close fully
Some blood that should go forward
to the body now comes back into the
heart
Causes:congenitally bicuspid valve
You hear the turbulence in diastole
after aortic valve should have fully
closed (after S2)
Diastolic Murmurs

Aortic Regurgitation (Upper Sternal)
• radiates inferiorly
• best heard with patient sitting up and
leaning forward (in expiration)
S1
S2
S1
Mitral stenosis
Mitral stenosis

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Mitral valve is tight so blood can not get out of
the atrium
When the mitral valve area goes below 2 cm,
the valve causes an impediment to the flow of
blood into the left ventricle, creating a pressure
gradient across the mitral valve.
Pressure=turbulence=murmur
Causes: Rheumatic heart dz, damage from
endocarditis
Sound: A mid-diastolic rumbling murmur will be
heard after an opening snap. The murmur is
best heard at the apical region and doesn’t
radiate
Patent Ductus Arteriosis (PDA)

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In some babies the ductus arteriosus
remains patent (connects pulm a and
aorta)
This opening allows oxygen-rich blood
from the aorta to mix with oxygen-poor
blood from the pulmonary artery.
This can put strain on the heart and
increase blood pressure in the lung
arteries.
PDA

Sounds like continuous machinery
murmur throughout systole and
diastole

Systolic
• Ventricular Septal Defect

Continuous
• Arteriovenous connections (PDA)
Split S2

Physiologically split S2
• Natural delay in closure of pulmonic valve
• Why? increase in pulmonary blood flow that occurs with
inspiration when increased venous return to the right
side of the heart delays the closure of the pulmonic
valve

Fixed Split S2= ASD
• Increase pulmonary blood flow from increased preload
from L->R shunt of blood across ASD delays closure of
pulmonic valve
• This split doesn’t change with respiration b/c ASD is
more hemodynamically significant than the small
increase in volume of blood that results from inspiration
Split S2

Paradoxically Split S2
• You have split S2 in EXPIRATION
• This can only happen when the aortic
valve is delayed in closing.
• A LBBB will cause delayed
depolarization of the left ventricle and a
slightly delayed closing of the aortic
valve!!
S3
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Only be heard with the bell, never with
the diaphragm .This helps distinguish it
clinically from a widely split S2.
Is heard after S2
It can be normal in children and young
people if no other abnormalities are
reported on exam.
If other abnormalities are reported or
the person is over 40, interpret this
sound as caused by the blood entering a
ventricle that is already volume and
pressure overloaded (like CHF)
S4
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Caused by blood entering a thickened,
stiffened ventricle.
Comes just before S1 in the cardiac cycle
Can be left or right sided
Can occasionally be heard in athletes but
more commonly found in ventricular
hypertrophy states or infiltrative
cardiomyopathies (amyloid etc)
Rubs
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Pericardial rub= pericarditis
This is a velcro sound that you can
hear throughout the cardiac cycle
Pericarditis
• Recent upper resp tract infection
• Chest pain that is better with leaning
forward and worse with lying down