Cardiac Valve Defects Flashcards

1
Q

Cardiac valve defects may be incompetent (regurgitant), stenosed or both. Abnormal valves produce turbulent flow which can be heard as a murmur on auscultation; a few murmurs are also felt as a thrill on palpation.

What is the S1 heart sound?

A
  • closure of mitral + tricuspid valves at start of isovolumetric contraction
  • VP > AP -> so AV valves close
  • valves open during end of diastole
  • soft if long PR or mitral regurgitation
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2
Q

What is the S2 heart sound?

A
  • closure of aortic + pulmonary valves
  • AortaP + Pulmp > ventricularp -> semilunar valves close
  • splitting during inspiration is normal
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3
Q

What is the S3 heart sound?

A
  • third heart sound - ‘ventricular gallop’
  • ‘kentucky gallop’ - (S1 - Ken, S2 - tuck, S3 - y)
  • caused by diastolic filling of ventricle
  • considered normal if < 30 yrs old (may persist in woman up to 50y)
  • heard in left ventricular failure (eg. dilated cardiomyopathy), constrictive pericarditis (aka pericardial knock) and mitral regurgitation
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4
Q

What is the S4 heart sound?

A
  • occurs just before S1 only if pathology present
  • ‘atrial gallop’
  • caused by atrial contraction against a stiff ventricle
  • may be heard in aortic stenosis, HOCM + hypertension
  • in HOCM a double apical impulse may be felt as a result of a palpable S4

S3 and S4 may occur together in what is known as a quadruple gallop or may merge to produce a summation gallop S7

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5
Q

What are examples of ejection systolic murmurs?

A
  • aortic stenosis
  • pulmonary stenosis, HOCM
  • ASD, Fallot’s
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6
Q

What are examples of pansystolic/holosystolic murmurs?

A
  • mitral/tricuspid regurgitation (high-pitched + ‘blowing’ in character)
  • VSD (‘harsh’ in character)
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7
Q

What are examples of late systolic murmurs?

A
  • mitral valve prolapse
  • coarctation of aorta
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8
Q

What are examples of early diastolic murmurs?

A
  • aortic regurgitation (high pitched + ‘blowing’ in character)
  • Graham-Steel murmur (pulmonary regurg, again high pitched + ‘blowing’ in character)
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9
Q

What are examples of mid-late diastolic murmurs?

A
  • mitral stenosis (‘rumbling’ in character)
  • austin-flint murmur (severe aortic regurgitation, again rumbling in character)
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10
Q

What is an example of a continuous machine-like murmur?

A

patent ductus arteriosus

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11
Q

What are the signs and symptoms of aortic stenosis and what is characteristic of this specific murmur?

A
  • ejection systolic murmur - right 2nd ICS
  • crescendo-decrescendo
  • radiates to carotids bilaterally
  • pitch = medium
  • symptoms*: dyspnoea, angina, exertional syncope, systemic emboli, sudden death
  • signs: slow rising carotid pulse, narrow pulse pressure, displaced, thrusting apex beat, soft S2 (absent S2 in severe disease), brachio-radial delay, late + weak pulse

*(SAD = syncope, angina, dyspnoea)

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12
Q

What are common causes of aortic stenosis?

A
  • cusp calcification of bicuspid aortic valve - calcification develops approx 30yrs w/ progressive stenosis, thought that years of turbulent flow across abnormal valve disrupt endothelium and collagen matrix of leaflets, resulting in gradual calcium deposition
  • age-related calcification of the normal tricuspid aortic valve - normal aortic valve is tricuspid where about 1-2% of pop have a bicuspid valve, it is thought cumulative wear + tear of valve motion over many years leads to endothelial + fibrous damage, causing calcificiation of an otherwise normal valve
  • post rheumatic fever valve disease (rare in UK)
  • congenital: William’s, Turner’s
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13
Q

What is the pathophysiology of aortic stenosis?

A
  • blood flow across aortic valve is impeded during systole
  • as a consequence, significantly elevated left ventricular pressure is necessary to drive blood into aorta
  • since AS develops over chronic course, the LV is able to compensate by undergoing hypertrophy in response to the higher systolic pressure it must generate to maintain output
  • ie. gradual development of LV outflow obstruction causes gradual pressure overload of LV + results in compensatory LV hypertrophy
  • however, hypertrophy reduces compliance of ventricle -> resulting elevation of diastolic** pressure -> **LA hypertrophy in order to fill the ‘stiff’ LV

as a consequence of the compensatory changes, there is a long asymptomatic period - eventually, the heart decompensates and there is deterioration in cardiac function leading to development of symptoms.

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14
Q

What are relevant investigations for aortic stenosis?

A
  • transthoracic echocardiogram - best for initial + subsequent evaluation of AS, used when there is an unexplaine dsystolic murmur, a single second heart sound, a history of a bicuspid aortic valve or symptoms that might be due to AS -> it shows elevated aortic pressure gradient
  • ECG - may show LVH and absent Q waves, AV block, hemiblock or bundle branch block
  • cardiac catheterisation - useful for diagnosis only when echo is inconclusive, shows elevated aortic pressure gradient
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15
Q

What does left ventricular hypertrophy look like on an ECG?

A
  • Results in increased R wave amplitude in the left-sided ECG leads (I, aVL and V4-6) and increased S wave depth in the right-sided leads (III, aVR, V1-3)
  • The most commonly used criteria are the Sokolov-Lyon criteria (S wave depth in V1 + tallest R wave height in V5-V6 > 35 mm)
  • ST segment depression and T wave inversion in the left-sided leads: AKA the left ventricular ‘strain’ pattern
  • Left axis deviation also common
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16
Q

What is the management of aortic stenosis in a clinically stable patient who is asymptomatic?

A
  • severe AS:
    • referral for surgical valve replacement if EF <50%
    • when surgery not performed, pts w/ severe AS should have echo every 6-12 months + regular clinical follow-up
  • non-severe AS - undergoing no surgery:
    • serial transthoracic echos every 3-5 years (mild AS) and 1-2 years (moderate AS)
  • non-severe AS - undergoing bypass, valve or aortic surgery:
    • concomitant prophylactic valve replacement
17
Q

What is the management of aortic stenosis for clinically stable patients who are symptomatic?

A
  • surgical aortic valve replacement - STS-PROM and EuroScore II are two risk assessment tools helpful for individual patient’s operative risk, valve replacement appropriate therapy for most symptomatic pts w/ severe AS, prosthetic aortic valves used in surgical valve replacement may be mechanical or bioprosthetic
  • long-term infective endocarditis antibiotic prophylaxis
  • long-term anticoagulation - in those pts who have had aortic valve replacement using prosthetic mechanical valves, not required if bioprosthetic valves used except in presence of AF
18
Q

What are the causes of mitral regurgitation?

A
  • MV prolapse
  • congenital cleft leaflets
  • MV annulus calcification
  • heart failure
  • Marfan’s
  • HOCM
  • MI
  • myxoma
  • papillary muscle rupture
  • overload
19
Q

What are the signs and symptoms of mitral regurgitation and what is characteristic of this specific murmur?

A
  • pansystolic - left 5th ICS
  • continuous character
  • radiates to left axilla
  • high pitch
  • symptoms:
    • acute - severe dyspnoea due to pulm oedema,
    • chronic - fatigue + exertional dyspnoea (allowing heart to compensate)
  • signs: soft S1, presence of S3, displaced thrusting apex beat
20
Q

What is the management of mitral regurgitation?

A
  • AF → control rate if fast + anticoag
  • Acute → nitrates / diuretics / positive inotropes
  • Severe → SURGERY
    • Repair over replacement is strong in degenerative regurgitation
21
Q

What are the signs and symptoms of tricuspid regurgitation and what is characteristic of this specific murmur?

A
  • pansystolic murmur - left 4th ICS
  • continous character
  • low pitch
  • symptoms: fatigue, symptoms of RVF
  • signs: signs of RVF
22
Q

What are the signs and symptoms of pulmonary stenosis and what is characteristic of this specific murmur?

A
  • ejection systolic murmur - left 2nd ICS
  • crescendo-decrescendo
  • radiates to left side of neck
  • medium pitch
  • symptoms: asymp, fatigue, syncope
  • signs: cyanosis

Can be caused by Noonan syndrome, rheumatic fever and carcinoid syndrome

23
Q

What are the causes of aortic regurgitation?

A
  • supravalvular aortic root disease
  • Marfan’s
  • CTD
  • atherosclerosis
  • dissecting aneurysm
  • bicuspid valve
  • infective endocarditis
24
Q

What are clinical features of aortic regurgitation?

A
  • High-pitched early diastolic murmur
  • collapsing pulse + wide pulse pressure
  • heaving apex
  • Quincke’s sign → capillary pulsation in nail beds
  • De Musset’s sign → head nodding w/ each heart beat
  • Corrigan’s sign → carotid pulsation

Usually presents w/ LV failure

Ix → ECG, CXR, ECHO, Cardiac catheterisation

25
Q

What is the management for aortic regurgitation?

A
  • Main goal is to reduce systolic HTN → ACE inhibitors
  • Echo every 6-12 months

Indications for surgery:

  • severe AR w/ enalarged ascending aorta
  • Increasing symptoms
  • Enlarging LV or deteriorating LV function on ECHO
26
Q

What is the biggest cause of mitral stenosis?

A

Rheumatic fever

27
Q

What is the clinical presentation of mitral stenosis?

A
  • Pulmonary HTN related
  • Dyspnoea, haemoptysis, chronic bronchitis-like picture
  • Hoarseness + dysphagia
  • Malar flush, low-vol pulse
  • AF common (due to enlarged LA)

Ix → ECG (p-mitrale), CXR, ECHO

28
Q

What is the management of mitral stenosis?

A
  • If in AF → rate control crucial
  • Anticoagulate w/ warfarin
  • Diuretics reduce preload and pulmonary venous congestion
  • If above fails to control symptoms → balloon valvuloplasty, open mitral valvotomy, or valve replacement