Cardio - Murmurs

Question 1

The first heart sound (S1) - what is it?

Answer 1

Closing of Atrioventricular valves at the start of systolic contraction of the ventricles

‘Lub’ sound

Question 2

The second heart sound (S2) - what is it?

Answer 2

Closing of the semilunar valves at the end of systolic contraction completion

‘Dub’ sound

Question 3

The third heart sound (S3) - what is it?

Answer 3

Heard roughly 0.1s after S2

It is the ‘sound’ of rapid ventricular filling

Normal in patients aged 15-40

Abnormal in older people - indication of heart failure

Question 4

The fourth heart sound (S4) - what is it?

Answer 4

Heard directly before S1

Always abnormal, hard to hear

Indicates stiff or hypertrophic ventricle

CAUSE - turbulent flow of blood from an atria into a non-compliant ventricle

Question 5

Auscultation - What is ERB’s point?

Answer 5

Third intercostal space on left sternal border - BEST area for listening to S1 and S2

Question 6

Assessing a murmur - SCRIPT

Answer 6

S - SITE, where is the murmur loudest?

C - CHARACTER, crescendo, decrescendo

R - RADIATION, can you hear over left axilla or carotids

I - INTENSITY, what grade of murmur

P - PITCH, indicates velocity

T - TIMING, systolic or diastolic

Question 7

What are the 6 murmur grades?

Answer 7

1 - difficult to hear

2 - quiet

3 - easy to hear

4 - easy to hear with palpable thrills

5 - easy to hear with stethoscope barely touching chest

6 - easy to hear with stethoscope off chest

Question 8

Hypertrophy or dilatation - What are the hypertrophic valvular disorders

Answer 8

Valvular HD can cause hypertrophy or dilatation

Stenotic valvular diseases cause muscle hypertrophy, due to the muscle having to push harder against a stenotic valve

Mitral stenosis - left atrial hypertrophy

Aortic stenosis - left ventricular hypertrophy

Question 9

Hypertrophy or dilatation - What are the dilatation valvular disorders

Answer 9

Valvular HD can cause hypertrophy or dilatation

When a leaky valve lets blood back into a chamber, stretches muscle resulting in dilatation

Mitral Regurgitation - left atrial dilatation

Aortic Regurgitation - left ventricular dilatation

Question 10

MITRAL STENOSIS:

1. What is it
2. Causes
3. Murmur type/sound

Answer 10

1. Narrow mitral V, difficult for blood to be pushed from LA to LV
2. Rheumatic HD, Infective Endocarditis (IE)
3. Mid-diastolic, low pitched rumbling murmur due to low velocity blood

Loud S1, due to thick AV valve requiring large systolic force to shut, then shutting suddenly

Question 11

MITRAL REGURGITATION:

1. What is it, and what does it cause
2. Causes
3. Murmur type/sound
4. Where does it radiate

Answer 11

1. Incompetent Mitral V, blood leaks back into LA during systolic contraction -> congestive cardiac failure -> due to leaking valve causing reduced ejection fraction and backlog of blood waiting to be pumped
2. Idiopathic (old age weakening), rheumatic HD, IE, connective tissue disorders
3. Pan-systolic, high pitched whistling murmur, due to high velocity blood through leaky valve
4. Left axilla

Question 12

AORTIC STENOSIS:

1. What is it, and what does it cause
2. Causes
3. Murmur type/sound
4. Where does it radiate

Answer 12

1. Most common valve disease. Blood flow during systole is slowest at very start and end of systole, and fastest in middle
2. Idiopathic age related calcification, Rheumatic HD
3. Ejection - systolic, high pitched murmur. Crescendo-decrescendo character, due to blood flow velocity during systole period
4. Radiates to carotids - turbulent blood continues up the neck

Slow rising pulse and narrow pulse pressure

Question 13

AORTIC REGURGITATION:

1. What is it
2. Causes
3. Murmur type/sound

Answer 13

1. Blood leaking back through aortic valve and into LV
2. Idiopathic age related weakness, connective tissue disorders
3. Early diastolic soft murmur, associated with collapsing pulse, as blood pumped out of ventricles, then immediately flows back down through aortic valve and into ventricles -> results in HF, due to back pressure of blood waiting to get pumped in left side of heart

Question 14

What are the special manoeuvres used to emphasise certain murmurs?

Answer 14

MITRAL STENOSIS - patient on left side

AORTIC REGURGITATION - patient sat up, leaning forward, holding exhalation

Question 15

Tricuspid Regurg - murmur sound and causes?

Answer 15

Pan-systolic

Causes:
right ventricular infarction
pulmonary hypertension e.g. COPD
rheumatic heart disease
infective endocarditis (especially intravenous drug users)
Ebstein's anomaly
carcinoid syndrome