Valvular heart disease Flashcards
How does valvular heart disease affect its preceding chamber?
A stenosed valve may cause its preceding chamber to experience pressure overload, which at lead to chamber hypertrophy.
Regurgitation tends towards volume overload, which may lead to chamber dilation and failure.
What is a murmur?
A murmur is defined as a pathological heart sound, produced over a region of turbulent blood flow.
How can murmurs be graded?
Using the Levine scale:
Grade I - very faint, almost inaudible
Grade II - quiet, audible
Grade III - clearly audible
Grade IV - loud with associated thrill
Grade V - very loud, with thrill, audible with rim of stethoscope
Grade VI - audible without stethoscope placed on chest
Causes of mitral stenosis
- Acute rheumatic fever is the most common cause (up to 95%); mitral steosis secondary to ARF is referred to as rheumatic heart disease
- Age related degenerative calcification
- Congenital valve deformity
- Rheumatological disorders
- Amyloidosis
Symptoms of mitral stenosis
(Symptoms tend to mimic those of heart failure)
- Dyspnoea (pulmonary congestion and interstitial oedema)
- Fatigue
- Palpitations (mitral stenosis strongly associated with AF - 47%)
- Hoarseness and dysphasia can result from a large left atrium compressing the recurrent laryngeal nerve and oesophagus (known as Ortner syndrome)
What is Ortner syndrome?
Ortner syndrome is characterised by hoarse voice resulting from left recurrent laryngeal nerve palsy secondary to a cardiovascular disorder.
Examination findings of mitral stenosis
- On auscultation:
- Loud S1
- Opening snap (pliable valve)
- Rumbling mid-diastolic murmur (heard best in expiration with patient on left side)
- Tapping, non-displaced, apex beat
- RV heave
- Atrial fibrillation common (due to enlarged LA)
- Malar flush (due to decreased cardiac output) and longer duration of the murmur are associated with more severe disease
Investigations for mitral stenosis
- Echocardiogram
- First line, diagnostic
- Transoesophageal echo may provide a more complete assessment of the valve
- ECG
- P-mitrale and AF are common
- Chest X-ray
- Left atrial enlargement may be seen
Management of mitral stenosis
- Anticoagulation
- Warfarin should be given if AF is present
- Treat AF
- Symptomatic relief
- Diuretics (decreases preload and pulmonary venous congestion)
- Beta blockers
- If that fails to control symptoms:
- Balloon valvuloplasty (if pliable, non-calcified valve)
- Open mitral valvotomy
- Valve replacement
Pathophysiology of mitral regurgitation
- Acute mitral regurgitation
- Papillary muscle infarction
- Ruptured chordae tendineae
- Infective endocarditis
- Trauma
- Chronic mitral regurgitation
- Mitral valve prolapse (most common cause in developed countries)
- Ischaemic mitral regurgitation (widening of the mitral valve annulus secondary to ventricular dilation)
- Rheumatic heart disease (most common cause in developing nations)
- Mitral valve calcification
- Connective tissue disease
- Coronary artery disease
Symptoms of acute mitral regurgitation
- Presents as an emergency
- Sudden onset severe dyspnoea and rapidly progressive pulmonary oedema
- Hypotension and cardiogenic shock
Symptoms of chronic mitral regurgitation
- Asymptomatic if mild or moderate
- Symptoms occur when left hear failure develops in severe mitral regurgitation
- At risk of AF (due to LA dilation)
Examination findings of mitral regurgitation
- Displaced apex beat
- Pan-systolic high pitched, (heard best with diaphragm of stethoscope) murmur radiating to the axilla
Investigations for mitral regurgitation
- Echocardiogram: first line, diagnostic, can assess severity of mitral regurgitation
- Obtain an ECG
- detection of AF, P-mitrale, acute/old MI
- Chest x-ray
- look for cardiomegaly, signs of heart failure or pulmonary oedema
Management of mitral regurgitation
- Anticoagulation
- if AF or severe LA dilation present
- Medical managment
- Diuretics, beta blockers and ACE inhibitors for symptomatic relief
- Surgical intervention
- Valve repair or replacement (severe symptomatic disease or severe asymptomatic disease with new onset AF or LV dysfunction
Define aortic stenosis and aortic sclerosis
Aortic stenosis refers to narrowing of the aortic valve orifice.
Aortic sclerosis, the preclinical phase to aortic stenosis, refers to calcification and thickening of the aortic valve without significant blood flow obstruction.
Epidemiology of aortic stenosis
- Third most common cardiovascular disease after coronary artery disease and hypertension in developed countries
- Prevalence increases with age, affecting 25% of those >65 years and almost 50% of those >85 years
Causes of aortic stenosis
- Calcification aortic stenosis (age related)
- Congenital bicuspid aortic valve
- Rheumatic heart disease - mostly in the developing world
Symptoms of aortic stenosis
- Classic triad of SAD symptoms on exertion
- Syncope (eg hypotension, transient arrhythmia)
- Angina
- Dysnpnoea (most common symptom)
Aortic stenosis on examination
- Ejection systolic murmur
- Slow rising and delayed pulse
- Narrow pulse pressure
Aortic stenosis investigations
- Echocardiogram
- narrow valve area is diagnostic (AV area ≤1cm = severe AS)
- ECG
- detection of LV hypertrophy, bundle branch block
Management of aortic stenosis
Aortic valve replacement or transcatheter aortic valve implantation
(Medical therapy (beta blockers, diuretics, ACE inhibitors) does not delay the time to valve replacement and is used only as a bridge to intervention of for those unfit for surgery.)
Indications for surgery for aortic stenosis include:
- Symptomatic severe AS
- Asymptomatic AS and LVEF <50%
- Patients with severe AS undergoing cardiac surgery for other indications
What are the pros and cons to mechanical and biological valves?
Mechanical valves are typically used in younger patients, but be aware that their use necessitates anticoagulation.
Biological valves do not requires anticoagulation if the patient does not have AF but they do not last as long as mechanical valves.
Definition of aortic regurgitation
Aortic regurgitation (AR) results from incomplete closure of the AV valves
Aetiology of aortic regurgitation
- Acute
- Infective endocarditis
- Aortic dissection or chest trauma
- Chronic
- Rheumatic heart disease
- Congenital anomalies (including bicuspid aortic valve)
- Connective tisssue disorders (Marfan, Ehler’s Danlos syndrome)
- Rheumatological conditions (rheumatoid arthritis, SLE)
Clinical features of acute aortic regurgitation
- Severe dyspnoea
- Pulmonary oedema
- Hypotension
Clinical features of chronic aortic regurgitation
Usually asymptomatic for many years before presenting with symptoms of heart failure.
Examination findings for aortic regurgitation
- High pitched early diastolic murmur, best heard on expiration at LLSE
- Collapsing pulse
- Pulsus bisferiens
- Wide pulse pressure
