Valve disease Flashcards
How can aortic stenosis present congenitally and as acquired?
Congenital
- Subaortic e.g. membrane, fibromuscular ring
- Valvular e.g. bicuspid valve
- Supravalvular e.g. Williams syndrome - narrowing of aorta just above the valve
Acquired
- Age-related degenerative calcific
- Rheumatic
What does AS cause and what are the symptoms?
Causes increased after-load, failure to increase CO during exertion, progressive LV hypertrophy (increased myocardial oxygen requirement), decreased systemic and coronary flow (decreased myocardial oxygen delivery)
Clinical presentation is exertional breathlessness, chest pain and dizziness
Usually insidious onset, sudden death
LV sustains increased CO until severe/critical so asymptomatic until this stage
What are physical findings and investigations in AS?
- Slow rising, low volume pulse
- BP - narrow pulse pressure
- Heaving apex beat (LVH)
- Ejection systolic murmur
(harsh ‘seagull’ in severe AS, aortic area/left sterna edge, radiates to carotids, loudst in expiration, may be very quiet in critical AS, quiet aortic component of S2)
Investigations - ECG for LV hypertrophy with strain and CXR for cardiomegaly (LVH) and pulomnary oedema
How would you quantify AS on echo?
- Use doppler
- Measure pressure difference (peak gradient) between LV outflow tract and aorta
calculation of pressure gradient is by modified Bernoulli equation:
Difference in pressure = 4(v2 squared - v1 squared)
Where v1<1.5 it is 4v2 squared
How do you get LV systolic pressure from pressure difference and how do you meure AS severity?
To get LV systolic pressure add onto sytolic BP so if 120 and pressure difference is 64 then LV systolic pressure would actually be 184mmHg
Mild <35mmHg
Mod 36-64
Severe >65
How would you manage AS?
- 1-5 yearly follow-up with echo
- Avoid vasodilators
- Consider intervention if symptomatic - severe
What are two main options in an intervention?
Surgical aortic valve replacement (general anaethetic, mortality risk, stroke.MI/bleeding risk)
Transcatheter aortic valve implant/replacement (TAVI/TAVR) - biological tissue valve, percutaneous or transapical approach
TAVI is minimally invasive but new technique so ? longevity
Indicated in very elderly, major co-morbities, risk of surgery prohibitive
Aortic regurgitation - how can this be caused?
Abnormal valve cusps
- Rheumatic disease
- Bicuspid valve
- Degenerative
- Consequences of endocarditis
Aortic disease
- HTN
- Aortoannular ectasia
- Marfan’s and other connective tissue diseases
- Dissection
Traumatic
What is pathophysiology of AR?
- Diastolic reflux of blood back into LV
- Volume overload
- Can cause Lv dilatation
- Better tolerated than pressure load chronically
Clinically presentation as breathless on exertion, orthopnoea, ankle swelling potentially
Physical findings in AR?
- Collapsing pulse
- Wide pulse pressure
- Displaced apex beat
- Early systolic murmur
High pitched
Left sternal edge/aortic area
Loudest in expiration whilst sitting forward
Often shorter when AR severe, longer when less severe
ECG and CXR investiations
Management of AR
- Annual follow up with echo
- Strict BP control to minimise aortic dilatation
- Consider surgery if symptomatic or left ventricle dilating
- Surgical AVR
How is mitral stenosis caused and what is pathophysiology?
Rehumatic fever or congenital
- Causes obstruction of normal transmitral flow (mainly positive), increased LA pressure to maintain flow (dilated LA)
- Increased pulmonary venous pressure - pulmonary congetion
Secondary right heart failure, tricuspid regurgitation
Rheumatic MS - how does this present?
Onset of symptoms 4th-5th decade, exertional breathlessness, HF symptoms, AF
Physical findings - AF (irregularly irregular pulse) - Tapping apex beat - Low pitched rumbling apical MDM - Mid-diastolic murmur Low pitched, apex, louder in left lateral position, louder after exertion, absence of silence
Investigations - ECG and CXR
MS management?
- Annual follow up with echo
- AF - increased rates poorly tolerated - BB/digoxin
- Anticoagulation
- If severe and symptomatic - consider intervention
(percutaneous balloon valvuloplasty, surgical valve replacement)
Balloon mitral valvuloplasty is first choice if valve is suitable, symptom relied, no general anaesthesia, catheter-based treatment via femoral vein, trans-septal puncture
Mitral regurgitation - what causes it?
Can be caused by leaflets, chordae, papillary muscles, annulus
Caused by rheumatics, degenerative, congenital, ischaemic or infective (endocarditis)
Clinical presentation of MR
Breathless on exertion, HF symptoms (orthopnoea, oedema)
Prognosis worsens with symptoms and Lv dilatation or systolic dyfunction
What are physical findings of MR and what investigations needed?
- May be in AF - irregularly irregular pulse
- May have displaced apex beat
- Pan systolic murmur (blowing, apex, radiates to axilla, volume relates to severity)
Investigations - ECG (AF) and CXR (cardiomegaly, pulmonary oedema)
What is mitral valve prolapse murmur?
- Can sound like typical mitral regurgitation murmur
- Late systolic
- Apex
- Radiates to axilla
MR management?
- Annual follow up with echo
- Intervention if breathless and severe MR and/or LV dilatation - mitral valve repair (valve reconstruction and annuloplasty so minimally invasive), mitral valve replacement, mitraclip (emerging procedure/patients not fit for open surgery), TMVR - trancatheter MV replacement - as per TAVI
Tricuspid regurgitation causes and physical findings
Causes - rheumatic, secondary to right heart dilatation, secondary to pulmonary HTN
Phyisically
- Right ventricular heave (secondary to primary cause)
- Pan systolic murmur - left sternal edge, less harsh than ventricular septal defect, loudest in inspiration
TR management
- Largely management of underlying condition - pulmonary embolism, chronic lung disease
- Rarely valve surgery (repair/replacement)
- Biological valve if possible - risk of thrombosis - low velocity flow
Tricuspid stenosis
Rare, rheumatic cause
Mid-diastolic mumrur - low pitched, left sternal edge, louder in inspiration
Annual echo, avoid surgery, biological valve if possible
Pulmonary regurgitation
Largely in congenital heart disease
Right ventricular heave, early disastolic murmur (high pitched, pulmonary area/left sternal edge, loudest in inspiration, accentuated sitting forward
Pulmonary stenosis
Right ventricular heave
Ejection systolic murmur - harsh, pulmonary area, loudest in inspiration, sitting forward may accentuate
Selection of valve replacement
Mechanical prosthesis or bioprosthesis
Mech - longevity and lower risk of needing repeat surgery but anticoagulation mandatory and no option for percutaneous intervention in future
Bio - no AC required, option of PCI later but less longevity and higher risk of needing repeat surgery
What are the post-op complications of valve replacement?
- Infective endocarditis
- valve thrombosis
- Regurgitation
- Stenosis
