Mitral valve defects Flashcards
Describe the mitral valve?
It has two leaflets only, anterior that cover most of the opening and posterior leaflet, typically it is 4-6 cm2 in area, anterior cusp is bigger, it resembles mitre, it is valve between left atrium and ventricle
What is mitral stenosis?
Narrowing of the mitral valve, it does not open fully
What are possible causes of mitral stenosis?
Rheumatic heart disease, systematic conditions such as systemic lupus erythematosus, rheumatoid arthritis
What is the reduction of the orificle size in mitral stenosis ?
From 4-6 cm2 to about 2 cm2
What is the outcome of the mitral stenosis?
Increased pressure in LA, pulmonary venous and capillary pressure is increased, this leads to pulmonary hypertension, due to hypertension the right side of the heart enlarges, there is tricuspid and pulmonary regurgitation, but LV functions normally
What happens to the left side of the heart in mitral stenosis?
There altered trans-valvular gradient and also flow rate, the CO is reduced, this can leads to tachycardia especially on exercise, acute illness, pregnancy
What are the symptoms of mitral stenosis?
Dyspnoea on exertion due to pulmonary oedema, haemoptysis as small blood vessels can rupture, chest pain, hoarseness of voice due to compression of the left recurrent laryngeal nerve, fatigue, palpitations
What are the signs of mitral stenosis?
mitral facies (red discolouration of cheeks, nose, rest of face has bluish tinge), low volume pulse, JVP prominent a wave, tapping apex beat and diastolic thrill, RV heave, diastolic decrescendo murmur, common AF
What investigations are needed for mitral stenosis?
ECG, echo, cardiac catheterisation, chest X ray, MRI
What can be observed in ECG?
prolonged P wave
What can be observed on chest X ray?
Enlarged LA
What is the treatment for mitral stenosis?
salt restriction, diuretics, anticoagulation and arrhythmic control if AF, valvotomy, mitral valve repair or replacement
What are complications of mitral stenosis?
Pulmonary hypertension, hoarseness, dysphagia, bronchial obstruction, IE, emboli
What is mitral regurgitation?
When the mitral valve becomes leaky
What are the causes of mitral regurgitation?
Rheumatic heart disease, degenerative causes, infective endocarditis, due to ventricle dilation
Describe the effective regurgitant orificle
It is not fixed, it depends on preload, after load, contractility
What is the difference between acute and chronic?
Acute presentation is an emergency, the ventricles do not have time to adapt, end systolic pressure and volume decreases, in chronic presentation ventricles have time adapt, they increase contractility to compensate, they also dilate to accommodate more blood
Describe the changes that occur in the left atrium in mitral regurgitation
LA has small compliance, pressure rise, thickening of the wall of myocardium, remodelling of pulmonary vasculature, pulmonary hypertension, can also develop fibrillation
Describe acute presentation of mitral regurgitation
Due to valve perforation, chrodea or papillary muscle prolapse, symtoms are breathlessness, cardiogenic shock
Describe chronic presentation of mitral regurgitation
fatigue, right heart failure, dyspnoea, palpitations due to AF, ventricles start failing especially on exertion, history from patients
Describe the signs of mitral regurgitation
normal or reduced pulse, JVP is prominent, hyper dynamic apex beat, RV heave, systolic murmur that is loud and can obscure the heart sounds, pan systolic murmur that radiates to the axilla
What are the investigations for mitral regurgitation?
ECG (bigger and longer P wave), chest X ray (LA and LV enlargement), echo, cardiac catherisation, cardiac catheterisation, cardiac MRI
What is the treatment for mitral regurgitation?
acute sodium nitropresside, dobutamine, chronic diuretics, valve repair or replacement
