30. Heart Murmurs Flashcards
What sound is S1? What causes this? When does this occur?
LUB
closing of mitral + tricuspid valves
At start of systolic contraction of ventricles
What sound is S2? What causes this? When does this occur?
DUB
Closing of aortic + pulmonary valves
After systolic contraction is complete (to prevent backflow)
What sound is S3? What causes this? When does this occur?
Lub(S1)- De(S2)-Dub(S3)
Rapid ventricular filling causing chordae tendonae to pull to full length
Subtle
.1s after 2nd heart sound
When is S3 normal? When is S3 pathological?
Normal: 15-40 yr olds
Pathological: older patients- can indicate HF as ventricles + chordae are stiff + weak
What sound is S4? What causes this? When does this occur?
Le (S4)- Lub (S1)- Dub (S2)
Turbulent flow from atria contracting against a ventricle that is non compliant.
Heard directly before S1
Is S4 normal? What does the presence of S4 suggest?
ALWAYS ABNORMAL
Indicates stiff or hypertrophic ventricle
List the 4 sites to auscultate for murmurs
Aortic valve 2nd ICS right sternal border
Pulmonary valve 2nd ICS left sternal border
Tricuspid valve 5th ICS left sternal border
Mitral valve 5th ICS MCL
What is ERBs point and why auscultate here?
Best place to listen to heart sounds (S1-4)
3rd ICS left sternal border.
How would you position a patient to listen for mitral stenosis?
Roll patient onto left hand side
How would you position a patient to listen for aortic regurgitation?
Sit patient up
Lean them forward
Ask them to take deep breath out + hold
What mnemonic can be used to assess heart murmurs?
SCRIPT
Site: Where is it loudest?
Character: Soft? Blowing? Crescendo? Decrescendo?
Radiation: can you hear murmur going to carotids? (AS) or left axilla? (MR)
Intensity: Grade?
Pitch: high pitched? low + grumbling? (velocity)
Timing: Systolic? Diastolic?
How do you grade a murmur?
1 = difficult to hear 2 = quiet 3 = Easy to hear 4 = Easy to hear with palpable thrill 5 = Hear with stethoscope barely touching chest 6 = Hear with stethoscope off chest, just holding nearby
Describe what commonly causes a heart to hypertrophy
When heart muscle is pushing against a stenotic valve, it has to work a lot harder to get blood through that valve
Describe the pathological effect of mitral stenosis on the heart
LA has to work really hard to push blood through the mitral valve, thus results in LA hypertrophy
Describe the pathological effect of aortic stenosis on the heart
LV has to work really hard to push blood through the aortic valve, thus results in LV hypertrophy
Describe what commonly causes heart dilatation
A leaky valve, allowing blood to flow back into the chamber stretches the muscle
Describe the pathological effect of mitral regurgitation on the heart
Blood flows back through the mitral valve into the LA, thus results in LA dilatation
Describe the pathological effect of aortic regurgitation on the heart
Blood flows back through the aortic valve into the LV, thus results in LV dilatation
Give 2 causes of mitral stenosis
Rheumatic heart disease
Infective endocarditis
Describe the murmur heard in mitral stenosis
Mid diastolic
Low pitched
Rumbling
Due to low velocity of blood flow
What sound is heard in mitral stenosis?
LUB! Dub Durrrrrr
Loud S1 as thick valves require large systolic force to shut
What 2 things may be found on examination in mitral stenosis?
Malar flush
Palpable tapping apex beat
What rhythm is mitral stenosis associated with?
Atrial fibrilation
Give 5 causes of mitral regurgitation
Idiopathic weakening of valve with age IHD Infective endocarditis Rheumatic heart disease Connective tissue disorders e.g. Marfaans
Describe the murmur heard in mitral regurgitation
Pan-systolic
High pitch whistling (High velocity through leaky valve)
Radiates to left axilla
What sound is heard in mitral regurgitation?
BURRRR (throughout systole)
What is mitral regurgitation associated with?
Congestive heart failure- leaking valve causes reduced ejection fraction, causes backlog of blood waiting to pass through left side of heart ∴ may hear S3 if HF present
Give 3 causes of aortic stenosis
Idiopathic age related calcification
Congenital bicuspid valve
Rheumatic heart disease
Describe the murmur heard in aortic stenosis
Ejection systolic- occurs while blood is being ejected from LV
High pitched
Crescendo-Decresendo due to speed of blood flow at different points of systolic contraction
Radiates to carotids as turbulence continues up to the neck
What sound is heard in aortic stenosis?
BURRRR-DUB
Give 2 signs on examination that aortic stenosis is associated with
Slow rising pulse
Narrow pulse pressure
Symptoms of what may accompany aortic stenosis?
Exertional syncope due to difficulty maintaining blood flow to the brain through that narrow valve
Give 2 causes of aortic regurgitation
Idiopathic age related weakness
Connective tissue disorders (Erhlers Danlos syndrome, Marfans)
Describe the murmur heard in aortic regurgitation
Early diastolic (Blood flow back through aortic valve happens during diastole)
Soft
VERY subtle
What sound is heard in aortic regurgitation?
Lub-tarrrr
What sign on examination is aortic regurgitation associated with?
Collapsing Pulse: rapidly appears then disappears as blood is pumped out of the ventricles then immediately starts flowing back through the aortic valve into the ventricles
What does aortic regurgitation often result in?
HF due to the back pressure of blood waiting to get back through the left hand side of the heart
What murmur may aortic regurgitation cause?
Austin Flint murmur
Heard at Apex
Early diastolic rumbling murmur
What is the most likely cause of a new onset pansystolic murmur in an IV drug user with fever?
Tricuspid regurgitation
due to infective endocarditis (S. aureus growing on tricuspid valve)
