Murmurs

Question 1

What are S1 and S2 caused by?

Answer 1

S1 - closing of the AV valves - tricuspid and mitral

S2 - closing of semilunar valves - pulmonary and aortic

Question 2

What extra heart sounds may be heard?

Answer 2

S3 - after S2:

• Can be normal in young patients
• Can indicate HF in older people

S4 - before S1:

• Always abnormal
• Rare
• Indicates a stiff or hypertrophic ventricle and is caused by turbulent flow from an atria contracting against a non-compliant ventricle.

Question 3

4 valve areas

Answer 3

Pulmonary: 2nd I.C.S left sternal border

Aortic: 2nd I.C.S right sternal border

Tricuspid: 5th I.C.S left sternal border

Mitral: 5th I.C.S mid clavicular line (apex area)

Question 4

Where is Erb’s point? Significance?

Answer 4

Third intercostal space on the left sternal border and is the best area for listening to heart sounds (S1 and S2).

Question 5

Special accentuation manoeuvres to listen for murmurs

Answer 5

Aortic stenosis:

• Diaphragm of stethoscope, listen to carotid while patient holds breath
• Ejection systolic murmur

Aortic regurgitation:

• Patient sits leaning forward - Listen with diaphragm over aortic area during holding expiration
• Early diastolic murmur

Mitral stenosis:

• Patient on their left hand side
• Listen with bell over mitral area during expiration
• Mid-diastolic murmur

Mitral regurgitation:

• Patient on left side
• Diaphragm over mitral area during expiration
• Pansystolic murmur
• Also listen in the left axilla for radiation

Question 6

Assessing a murmur - describing a murmur

Answer 6

S – Site: where is the murmur loudest?
C – Character: soft / blowing / crescendo (getting louder) / decrescendo (getting quieter) / crescendo-decrescendo (louder then quieter)
R – Radiation: can you hear the murmur over the carotids (AS) or left axilla (MR)?
I – Intensity: what grade is the murmur?
P – Pitch: is it high pitched or low and grumbling? Pitch indicates velocity.
T – Timing: is it systolic or diastolic?

Question 7

Murmur grade

Answer 7

1. Difficult to hear
2. Quiet
3. Easy to hear
4. Easy to hear with a palpable thrill
5. Can hear with stethoscope barely touching chest
6. Can hear with stethoscope off the chest

If in doubt - probably a grade 2 or 3

Question 8

What murmurs lead to hypertrophy, what cause dilatation?

Answer 8

When pushing against a stenotic valve the muscle has to try harder resulting in hypertrophy:

• MS causes left atrial hypertrophy.
• AS causes left ventricular hypertrophy.

When a leaky valve allows blood to flow back into a chamber it stretches the muscle resulting in dilatation:

• MR causes left atrial dilatation.
• AR causes left ventricular dilatation.

Question 9

Mitral stenosis causes

Answer 9

Rheumatic heart disease

Infective endocarditis

Question 10

Mitral stenosis murmur presentation

Answer 10

Mid-diastolic
Low pitched (rumbling)
Loud S1 due to thick valves requiring large systolic force to shut
Can palpate tapping apex beat (due to loud S1)

• Loud S1, second heart sound followed by rumbling murmur
• Sounds a bit like LUB dub drrr (rumbling murmur after quieter S2)

Associated with:

• Malar flush - due to back-pressure of blood into the pulmonary system causing a rise in CO2 and vasodilation.
• Atrial fibrillation - caused by the left atrium struggling to push blood through the stenotic valve causing strain, electrical disruption and resulting fibrillation.

Question 11

Mitral regurgitation pathophysiology

Answer 11

Incompetent mitral valve allows blood back into the left ventricle during systolic contraction

Results in CCF as it causes reduced EF

Question 12

Mitral regurgitation murmur presentation

Answer 12

Pan-systolic murmur

High pitched - whistling murmur

Murmur radiates to left axilla

May hear S3

Sounds a bit like brrr, brrr, brrr (because murmur occurs entire way through systole)

Question 13

Causes of mitral regurgitation

Answer 13

Idiopathic weakening of the valve with age
Ischaemic heart disease
Infective Endocarditis
Rheumatic Heart Disease
Connective tissue disorders such as Ehlers Danlos syndrome or Marfan syndrome

Question 14

Aortic stenosis murmur presentation

Answer 14

Ejection systolic murmur
Crescendo-decrescendo
Radiates to the carotids

Slow rising pulse and narrow pulse pressure

Patients may have exertional syncope

Sounds a bit like brrr dub, brrr dub
- Systolic murmur that gets louder and quieter

Question 15

Causes of aortic stenosis

Answer 15

Idiopathic age related calcification

Rheumatic heart disease

Question 16

Aortic regurgitation murmur presentation

Answer 16

Early diastolic soft murmur

Test for collapsing pulse - fingers on pulse and raise arm above head - positive if water hammer pulse against fingers

Wide pulse pressure
Bounding pulse

Accentuation manoeuvre - leaning forward, diaphragm listen in aortic area during expiration

Sounds a bit like lub tarrrr, lub tarrrr

Question 17

Causes of aortic regurgitation

Answer 17

Idiopathic age related weakness

Connective tissue disorders such as Ehlers Danlos syndrome or Marfan syndrome

Question 18

Consequences of aortic regurgitation

Answer 18

Aortic regurgitation results in heart failure due to a back pressure of blood waiting to get through the left side of the heart.

It can also cause an “Austin-Flint” murmur. This is heard at the apex and is an early diastolic “rumbling” murmur. This is caused by blood flowing back through the aortic valve and over the mitral valve causing it to vibrate.