Heart Sounds and Murmurs
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Transcript Heart Sounds and Murmurs
Heart Sounds and Murmurs
J.B. Handler, M.D.
Physician Assistant Program
University of New England
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Abbreviations
A- aortic
P- pulmonic
T- tricuspid
M- mitral
AV- atrioventricular
SL- semi-lunar
SB- sternal border
ASD- atrial septal defect
AR- aortic regurgitation
AS- aortic stenosis
TR- tricuspid regurgitation
PVR- peripheral vascular
resistance
IO- interest only
CHD- coronary heart disease
MR- mitral regurgitation
MS- mitral stenosis
SEM- systolic ejection
murmur
MVP- mitral valve prolapse
LBBB- left bundle branch
block
ICS- intercostal space
RV- right ventricle
LV- left ventricle
LA- left atrium
RA- right atrium
PS- pulmonic stenosis
PR- pulmonic regurgitation
LLD-left lateral decubitus
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Listening Points/Positions
Aortic: “base”- 2nd Rt ICS, SB
Pulmonic: “base”- 2nd Lt ICS, SB
3rd Lt ICS, SB
Tricuspid: lower Lt sternal border(4-5ICS)
Mitral: cardiac apex (LV) 5ICS, MCL
Sitting, lying, left lateral decubitus (s3,4
gallops, and mitral stenosis)
Internet sites for heart sounds: http://www.cardiologysite.com
http://www.blaufuss.org/
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Auscultation Areas
Heart Sounds
S1- mitral/tricuspid valve closure.
S2- aortic/pulmonic valve closure.
Distinguishing S1 vs S2
-Listen at apex, palpate carotid-S1 precedes
carotid pulse.
-Intensity of S1>S2 at apex (reverse at base).
-S1 immediately precedes the PMI.
S1 occasionally splits with inspiration
(.02-.03 seconds)…difficult to hearMV
closes before TV, accentuated with
inspiration.
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S2 Splitting
IO
Commonly heard in inspiration
(separation of A2 and P2 is .02-06 Sec).
A2 normally precedes P2- accentuated in
inspiration because RV volume increases,
LV volume decreases………..why?
Fixed splitting: ASD.
Paradoxical splitting: Aortic valve closure
is delayed, closes after pulmonic.
P2 precedes A2 . During inspiration they move
together, in expiration they move apart.
Examples: Aortic Stenosis, LBBB.
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Splitting of 2nd Heart Sound
3rd Heart Sound vs S3
Gallop
3rd heart sound: Low pitched sound, .1-.2 sec
post S2. May be heard in young, healthy
people. Reflects rapid inflow of blood into
normal, compliant LV.
S3 gallop: abnormal “dull thud” in mid diastole.
LV dysfunction and dilation often present (CHF).
Also heard with MR, AR with volume overload.
Pathophys: 1. Sudden deceleration of blood flow
into diseased, dilated & non compliant ventricle.
2. AR/MR- volume overload with rapid inflow of
increased blood volume into compliant LV.
Best heard: bell at apex in LLD position.
Timing: lub….du..dub
S1
S2
S3
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S4 Gallop
Almost always abnormal
Short, low frequency, precedes S1
“presystolic gallop”.
Pathophys: Atrial contraction into noncompliant ventricle.
Conditions: LVH (HTN, AS), CHD
(ischemia or infarction).
Best heard: bell at apex in LLD position.
Timing: bu.lub….dub
S4
S1
S2
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Murmurs: Grading Scale
Grade I- Very faint; barely audible. Often
heard only by experienced clinicians.
Grade II- soft, but audible
Grade III- moderately loud
Grade IV- loud with associated thrill
Grade V- very loud + thrill; audible with
diaphragm on end.
Grade VI- very loud + thrill; audible with
stethoscope off chest.
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Murmurs: Radiation
Depends on direction of blood flow
responsible for the murmur, duration of
and intensity of the murmur.
Aortic outflow murmurs (AS) radiate from
the cardiac base/aortic area to base of
neck or carotids.
Most MR murmurs radiate to axilla.
AR murmurs radiate down LSB
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Murmurs: Description
Intensity: see grading scale
Quality: Blowing, harsh, grating, rumble.
Pitch: High vs low pitched
Timing: Early/mid/late systolic vs.
holosystolic. Early/mid diastolic.
Configuration: Crescendo-decrescendo,
decrescendo, plateau, others.
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Murmur Timing and Configurations
Murmurs: Use of Maneuvers
Respiration: Inspiration RV
filling/volume. Murmurs arising from Rt
side of heart (PS, PR, TR) get louder
during inspiration and reverse in
expiration.
Valsalva: Net effect is venous return to
RV; RV followed by LV volume.
Squatting: venous return to heart;
PVR and BP. Net effect: LV and RV
volumes.
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Murmurs: Use of Maneuvers
Rapid upright posture after squatting:
venous return to RV, PVR. Net
effect:RV and LV volumes.
Isometric exercise (handgrip):PVR and
BP, CO/HR. Net effect- makes murmurs
of MR and AR louder. Avoid in patients
with myocardial ischemia and
ventricular arrhythmias.
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Murmurs: Maneuvers
Outflow murmurs across aortic and pulmonic
valves (includes AS, PS and innocent murmurs)
get louder with maneuvers that LV/RV volume
and softer with LV/RV volume.
Insufficiency Murmurs: AR, MR, TR act similarly
to above.
Exceptions: Murmur of MV prolapse and
hypertrophic cardiomyopathy get louder with
maneuvers that LV volume and softer with
reverse physiology.
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Characteristic Systolic
Murmurs
Innocent or functional murmurs: arise from
pulmonic or aortic outflow tracts in the presence
of normal pulmonic/aortic valves. Common in
young, healthy individuals. Usually Grade I
or II, get louder with squatting and very soft or
absent with standing/valsalva. Mid-systolic,
short.
Aortic stenosis: harsh, often loud, best heard
base/aortic area, C/D (crescendo/decrescendo),
radiate to neck/carotids. Length of murmur
correlates with severity of obstruction. Best
heard with diaphragm.
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Characteristic Systolic
Murmurs
Mitral regurgitation: high pitched, blowing,
best heard at apex, holosystolic (if not acute),
radiates to axilla. Best heard with diaphragm.
MV prolapse with MR: high pitched, blowing,
best heard at apex, mid to late systolic and
often preceded by valve click. Characteristic
changes with maneuvers (see above). Best
heard with diaphragm.
Pulmonic stenosis (congenital defect): harsh,
best heard at base/pulmonic area, C/D radiates
down LSB. Louder in inspiration.
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Characteristic Diastolic
Murmurs
Aortic regurgitation/insufficiency:
high pitched, blowing, best heard along
LSB, 2nd/3rd ICS, decreshendo, begins
with S2, radiates down LSB. Best heard
with diaphragm.
Mitral stenosis: low pitched, rumbling,
best heard at apex, mid diastolic. Best
heard with bell- easily missed with
diaphragm.
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