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