Cardiology - Valvular Heart Disease Flashcards
What is the cause of
a) the first heart sound (S1)?
b) the secondary heart sound (S2)?
a) closing of the atrioventricular valves at the start of systolic contraction
b) closing of the semilunar valves once systolic contraction is complete
What is a 3rd heart sound (S3)?
A heart sound heard roughly 0.1s after S2, caused by rapid ventricular filling causing the chordae tendinae to ‘twang’.
In younger patients (aged 15-40yrs) this can be normal - heart functions so well it allows rapid ventricular filling during diastole.
In older patients S3 can indicate heart failure - the ventricles and chordae are stiff and week so they reach their limit much faster than normal.
What is a fourth heart sound (S4)?
A heart sound heart directly before S1, caused by turbulent flow from an atria contracting against a non-compliant ventricle.
It is always abnormal and can indicate a stiff of hypertrophic ventricle.
Anatomically describe the 4 valve areas to listen for murmurs.
Pulmonary valve: 2nd ICS, left sternal border
Aortic valve: 2nd ICS, right sternal border
Tricuspid valve: 5th ICS, left sternal border
Mitral valve: 5th ICS, mid-clavicular line
What is Erb’s point?
The best area for listening to heart sounds S1 and S2.
In the 3rd ICS, left sternal border.
Outline how to assess a murmur.
SCRIPT mnemonic:
Site - where is the murmur the loudest?
Character - soft / blowing / crescendo (getting louder) / decrescendo (getting quieter) / crescendo-decrescendo (louder then quieter)?
Radiation - can you hear the murmur over the carotids (AS) or left axilla (MS)
Intensity - what grade is the murmur?
Pitch - high pitched / low and grumbling?
Timing - systolic / diastolic?
When pushing against a stenotic valve, the myocardium has to try harder resulting in hypertrophy.
a) mitral stenosis causes:
b) aortic stenosis causes:
a) left atrial hypertrophy
b) left ventricular hypertrophy
When a leaky valve allows blood to flow back into a chamber, the myocardium stretches resulting in dilatation.
a) mitral regurgitation causes:
b) aortic regurgitation causes:
a) left atrial dilatation
b) left ventricular dilatation
What are the three cardinal symptoms of aortic stenosis?
SAD:
Syncope
Angina
Dyspnoea
The most common initial symptom is a decrease in exercise tolerance, causing dyspnoea upon exertion.
What are the causes of aortic stenosis?
- idiopathic age-related calcification
- rheumatic heart disease
- congenital bicuspid valve
- chronic kidney disease
Describe the murmur typical of aortic stenosis.
Site: 2nd ICS, right sternal border
Character: crescendo-decrescendo character
Radiation: radiates to the carotids
Intensity:
Pitch: high-pitched murmur
Timing: ejection systolic (between S1 & S2)
How is aortic stenosis investigated?
Echocardiography allows quantification of the severity of the stenosis, and assessment of the rest of the heart.
How is aortic stenosis managed?
Heart valve surgical intervention indicated if:
- symptomatic AS
- asymptomatic severe AS with left ventricular systolic dysfunction
- asymptomatic severe AS with abnormal exercise test
- asymptomatic severe AS at the time of other cardiac surgery
In older patients, transcatheter aortic valve implantation (TAVI) can be implanted via the femoral artery.
Presentation of aortic regurgitation?
Asymptomatic for many years.
Aortic regurgitation causes left ventricular dilatation, and ultimately heart failure. The first symptoms of aortic regurgitation are usually consistent with those of heart failure: exertional dyspnoea and reduced exercise tolerance.
What are the causes of aortic regurgitation?
- idiopathic age related weakness
- connective tissue disorders (e.g. Ehler’s Danlos syndrome or Marfan’s)
- congenital bicuspid valve
- infective endocarditis
Describe the murmur typical of aortic regurgitation.
Site: 2nd ICS, right sternal border
Character: soft murmur
Radiation: N/A
Intensity:
Pitch: low-pitch
Timing: early diastolic (after S2)
OE Corrigan’s pulse (collapsing pulse) and head bobbing also associated with aortic regurgitation.
Assessment of aortic regurgitation?
Echocardiography allowing quantification of the severity of the regurgitation, and assessment of the rest of the heart.
Management of aortic regurgitation?
Heart valve surgical intervention indicated if:
- symptomatic severe AR
- asymptomatic severe AR with evidence of early LV systolic dysfunction
- asymptomatic AR with aortic root dilatation
What is mitral regurgitation?
A heart murmur as a consequence of an incompetent mitral valve allowing blood to leak back through during systolic contraction, causing dilatation of the left atria.
It results in congestive heart failure because the leaking valve causes a reduced ejection fraction, and a backlog of blood that is waiting to be pumped through to the left side of the heart.
What are the symptoms of mitral regurgitation?
Asymptomatic for many years.
Most patients with chronic MR have mild-moderate disease and are unlikely to ever need surgical intervention.
What are the causes of mitral regurgitation?
- idiopathic weakening of the valve with age
- ischaemic heart disease
- infective endocarditis
- Rheuamatic heart disease
- connective tissue disorders (e.g. Ehler’s Danlos syndrome)
Describe the heart murmur typical of mitral regurgitation.
Site: 5th ICS, left mid-axillary line
Character:
Radiation: radiates to left axilla
Intensity:
Pitch: high-pitched ‘whistling’
Timing: pan-systolic
Assessment of mitral regurgitation?
Echocardiography to assess LV function and size.
Management of MR?
Heart valve surgical intervention indicated if:
- symptomatic severe MR
- asymptomatic severe MR with mild-moderate LV dysfunction
Note surgical intervention rare in MR, with medical intervention more common, including:
- diuretics
- ACEi
- beta-blockers
