Valvular dysfunction Flashcards
The main causes of valvular dysfunction.
Fibrosis: fusion of leaflets due to excess connective tissue.
Calcification: reduce mobility of leaflets due to deposits.
Dilatation of valve ring: prevents valve from closing and can cause prolapse.
Epidemiology of degenerative valve disease
Seen to increase with age.
More present in aortic than mitral valve.
Epidemiology of rheumatic valve disease
Prevalent after post Strep. rheumatic fever (not common in the West).
More common in children and young adults.
Seen in areas high with poverty due to overcrowding.
More present in mitral than aortic valve.
Epidemiology of Infective valve disease
More commonly seen with already abnormal valves.
Seen in immunocompromised individuals.
Very virulent organisms (Staph/ strep) can infect normal valves.
Can affect any valve but is more common to the left heart.
Right heart more affected in intravenous drug users (IVDU)
Aetiology of valve diseases
Degeneration
Rheumatic
Infective
Secondary loss of supportive tissue
Congenital causes
Regurgitation
Occurs when valves do not close properly, causing blood to leak back into the previous chamber
Stenosis
Narrowing of the leaflets, preventing the valve from closing properly.
Aortic stenosis aetiology
Mainly caused by degenerative factors, seen in people over 60.
Congenital causes: in paediatric cases and people under 60. Very low incidence in all populations.
Post rheumatic fever- people under 60
Bicuspid valves due to fibrosis: 40-60 years old
Symptoms of aortic stenosis
Low perfusion so: Chest pain (angina) Heart murmurs Syncope Dyspnea Arrhythmia
Consequences of aortic stenosis
Pressure overload:
Left ventricular compensation causes an increase in systolic pressure because of increased afterload.
Left ventricular hypertrophy
Leads to eventual decompensation and dilatation.
Aortic stenosis heart sounds.
Crescendo/ descendo murmur
No distinct ‘lub-dub’
Aetiology of aortic regurgiatation
Aortic dilatation:
- Degenerative
- Secondary loss of structural, supportive tissue.
- Connective tissue disease (rheumatic)
- Ventricular hypertrophy
- Aortic dissection, tear can pull the aorta and aortic valve backwards.
Valvular:
- Bicuspid valve (aortic valve should be tricuspid)
- Infective endocarditis
Acronym for causes: CREAM C ongenital R heumatic damage E ndocarditis A ortic dissection/ root dilatation M arfan's
Symptoms of aortic regurgitation
Mainly asymptomatic BUT these can occur:
Chest pain
Dyspnea
Pulmonary oedema can occur if acute decompensation is prevalent
Heart sounds in aortic regurgitation
Early diastolic murmur is heard
There is still a clear systolic ‘lub’
Sometimes a systolic murmur could also occur
Consequences of aortic regurgitation
Left ventricle dilatation + failure—-> Left atrium enlargement —-> Pulmonary vein hypertension —-> Pulmonary oedema
Mitral valve regurgitation aetiology
Valvular causes:
- Chordal rupture/ papillary muscle failure
- Annular dilatation
Symptoms of mitral valve regurgitation
Lethargy/ reduced tolerance to exercise
Dyspnea
Atrial fibrillation
Peripheral oedema
Chest pain
Mitral valve regurgitation heart sounds
Pansystolic murmur, with an audible diastolic ‘dub’
Consequences of mitral valve regurgitation
Potential consequences:
Volume overload in Left ventricle
Pressure overload in the right heart
Left ventricular dilatation
Potential heart decompensation
Mitral stenosis aetiology
Almost always due to rheumatic fever
Other potential causes: Congenital Mitral valve calcification Malignancy Previous endocarditis
Symptoms of mitral stenosis
Dyspnea
Haemoptysis
Palpitations
Systemic emboli
Stridor
Dysphagia
Mitral stenosis heart sounds
Mid-diastolic murmur, low pitched descendo-crescendo
Consequences of mitral stenosis
Lung and right heart suffer due to build up of back pressure- not enough blood pumped by left atrium.
Left ventricle is compromised-
Low filling due to less blood pumped by atrium.
Medical management of valvular dysfunctions
Mainly dealing with the consequences/ symptoms rather than the actual valve.
Same treatment as that of heart failure:
Diruetics
Arrhythmia control drugs
Surgical management of valvular dysfunctions
Valvular repair or valvular replacement.
Valvular repair is the better option as original tissue is kept, less chance of complications.
Valve replacement: bovine or mechanical valve placed in replacement of faulty valve.
Mitral valve heart sound
Mid-systolic click and late systolic murmur
Transcutaneous valve replacement
Non-invasive surgery that uses a needle to get access to the valve via the artery.
Example: balloon angioplasty valve replacement- used for aortic valve dysfunctions