Cardio - Murmurs Flashcards
The first heart sound (S1) - what is it?
Closing of Atrioventricular valves at the start of systolic contraction of the ventricles
‘Lub’ sound
The second heart sound (S2) - what is it?
Closing of the semilunar valves at the end of systolic contraction completion
‘Dub’ sound
The third heart sound (S3) - what is it?
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
The fourth heart sound (S4) - what is it?
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
Auscultation - What is ERB’s point?
Third intercostal space on left sternal border - BEST area for listening to S1 and S2
Assessing a murmur - SCRIPT
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
What are the 6 murmur grades?
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
Hypertrophy or dilatation - What are the hypertrophic valvular disorders
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
Hypertrophy or dilatation - What are the dilatation valvular disorders
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
MITRAL STENOSIS:
- What is it
- Causes
- Murmur type/sound
- Narrow mitral V, difficult for blood to be pushed from LA to LV
- Rheumatic HD, Infective Endocarditis (IE)
- 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
MITRAL REGURGITATION:
- What is it, and what does it cause
- Causes
- Murmur type/sound
- Where does it radiate
- 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
- Idiopathic (old age weakening), rheumatic HD, IE, connective tissue disorders
- Pan-systolic, high pitched whistling murmur, due to high velocity blood through leaky valve
- Left axilla
AORTIC STENOSIS:
- What is it, and what does it cause
- Causes
- Murmur type/sound
- Where does it radiate
- Most common valve disease. Blood flow during systole is slowest at very start and end of systole, and fastest in middle
- Idiopathic age related calcification, Rheumatic HD
- Ejection - systolic, high pitched murmur. Crescendo-decrescendo character, due to blood flow velocity during systole period
- Radiates to carotids - turbulent blood continues up the neck
Slow rising pulse and narrow pulse pressure
AORTIC REGURGITATION:
- What is it
- Causes
- Murmur type/sound
- Blood leaking back through aortic valve and into LV
- Idiopathic age related weakness, connective tissue disorders
- 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
What are the special manoeuvres used to emphasise certain murmurs?
MITRAL STENOSIS - patient on left side
AORTIC REGURGITATION - patient sat up, leaning forward, holding exhalation
