Valvular heart disease - Pathophysiology, Presentation and Investigation Flashcards
What are the common heart valve lesions?
-Pulmonary heart valve sits most anteriorly
-Behind the pulmonary valve directly is the aortic valve. Aortic valve sits at the interface between the left ventricle and the aorta
-Behind the pulmonary and the aortic valve there is the tricuspid valve and the mitral valve
How many leaflets is each valve made out of?
Pulmonic, aortic and tricuspid are made of three leaflets. Mitral valve is made out of two leaflets.
How does mitral valve interact with the left ventricle?
At the top of the mitral valve leaflets there is spindly structures called as chordae tendinea that connect the tips of the mitral valve leaflets to papillary muscles. These papillary muscles insert themselves into the ventricle.
What is the role of the aortic valve?
Aortic valve is responsible for the ejection of the stroke volume into the circulation. It has 3 cusps which are equal in size and symmetric. Normal aortic valve area is 3-4 cm squared. Aortic valve is at the outlet of the left ventricle.
What is stenosis?
narrowing of the valve leaflet and regurgitation or leakage or incompetence (not keeping the seal it should be keeping)
What is the cause for mitral stenosis?
The most common reason for someone to develop mitral stenosis is rheumatic heart disease. Years after having rheumatic heart disease patients present with thickening, scarring and fusion of the mitral valve leaflets.
Very rarely patients are born with mitral stenosis. It can also be encountered, although to a very mild degree, in systemic conditions such as lupus or rheumatoid arthritis.
What happens in mitral stenosis?
- Mitral stenosis is talked about when the orifice is smaller than 2 square cm. Normal orifice is between 4-6 squared sm.
- Due to narrowing of mitral valve orifice, pressure gradient between atrium and ventricle increases
- Left atrial pressure will then increase and everything backtracks into pulmonary circulation. Patients develop increased pulmonary vascular resistance
- Then develop increased pulmonary artery pressure (pulmonary hypertension)
- Later stages everything bacck tracks into the right heart and patient develops right heart dilation with tricuspid regurgitation because of left heart valve
What happens to the severity of the disease and the left ventricular function?
In mitral stenosis because the narrowing is at the inflow of the ventricle, the ventricle doesn’t get pressure overloaded or volume overload so therefore the left ventricular pressure in systolic function is normal.
What are the symptoms of mitral stenosis?
- Dyspnea - This can be from mild exertional breathlessness to pulmonary oedema
- Hemoptysis - This is due to rupture of the thin walled vessels in the pulmonary circulation
- Systemic embolisation - Due to dilation of the Left Atrium and Left atrial appendage. Blood becomes stagnant in the left atrium, clots form and they get ejected into the systemic circulation
- IE (infective endocarditis)
- Chest pain
- Hoarsness
What is found on clinical examination in mitral stenosis?
- Pulse - normal
- JVP - prominent a wave
- Tapping apex beat and diastolic thrill
- RV heave
- Ausciltation: Will hear two normal heart sounds. Systole is empty. When mitral valve becomes calcified the opening of the mitral valve can lead to a third heart sound called the opening snap.
- Mitral facies - Red plethoric cheeks
What is the investigation of mitral stenosis?
- ECG - There is longer and taller p waves because of the left atrial dilatation and right ventricular hypertrophy with prominent R waves in V1 nad V2
- Cardiac Catherisation - Not done anymore.
- Chest X-ray - You may see on CXR straighteneing or bulding of the left heart borded because of the left atrium enlargement
- Imaging - MRI
What is the medical treatment of mitral stenosis?
-Diuretics and restriction of sodium intake
- If patients develop atrial fibrilation, try and bring them back to sinus rhythm to restore the normal rhythm of the heart as much as possible
- Anticoagulation - Complusory is they are in atrial fibrilation in order to prevent stroke
- For severe mitral stenosis, the valve is replaced.
- Temporary solution is balloon valvotimy. In this you put a balloon into the mitral valve, you inflate the balloon and release the conventional fusion
What is the cause for mitral regurgitation?
Most common reason for mitral regurgitation is the rheumatic heart disease. In the Uk the most common cause is mitral valve prolapse. Valve can become infected and in older population it becomes degenerative.
What are three elements with mitral regurgitation depend on?
Effective regurgitate orifice is not fixed. It depends on the preload, afterload and depends on the ventricular contractility on how severe the mitral regurgitation, when you assess it, may appear to you.
These three elements also dictate how the ventricle reacts to mitral regurgitation depending on whether it ocurs acutely or chronically
How does the left atrium behave?
Left atrium behaves differently as well depending on the left atrium myocardium which determines from person to person. It can react in two different ways
What is the first way the left atrium can behave in?
If the left atrial compliance is reduced, which means it doesn’t want to dilate. The marked pressure airses and there is thickenoing of atrial myocardium. This results in increase in PVR and remodelling of the pulmonary vasculature with PHT
What is the other way the left atrium can behave in?
If the left atrial myocardium is enlarged. The left atrium is going to get bigger and will contain on the blood volume and will become very stagnant. This risk of this is atrial fibrillation and embolisation.
What are the clinical manifestations of acute mitral regurgitation?
Breathlessness
Pulmonary oedema
Cardiogenic shock
What are the clinical manefestations of chronic mitral regurgitation?
Fatigue
Exhaustion
Right heart failure
Dysponea
Palpitations due to atrial fibrilation,
What is found on clinical examination of mitral regurgitation?
- Pulse is normal
- Venous pressure is elevated
- Brisk apex beat
- RV heave
- Auscaltation: Systole is occupied. Will hear the first heart sound. Then you will hear obvious systolic murmur of mitral regurgitation. Second heart sound and then the diastole is empty. The murmur of mitral regurgitation is hollow. Best heard on with the patient when they are turned on the left side, radiates to the axilla.
What are the investigation of mitral regurgitation?
- ECG: Left atrial enlargement with a more prominent p-wave and right ventricular hypertrophy with a prominent R wave
- Chest X-Ray shows the left atrial enlargemennt
- Cardiac Catherisation is obselete in mitral regurgatioN
- Imaging - Echocardiography: shows the amount and severity of mitral regurgitation, shape of the leaflets and the LV dimensions. MRI
How is acute mitral regurgitation treated?
Need to decrease the preload and afterload as much possible and to increase the contractility of the ventricles. This is done by the isotropic stimulation, dibutamine.
How is chronic mitral regurgitation treated?
Wait to see how the severity develops. See whether the patients develop symptoms or whether the left ventricular function starts to decline, which are indicators for intervening. Intervening involves repairing the mitral valve, usually done surgically or replacing the mitral valve. Mitral valve repair can also done percuataneously.
What is aortic stenosis?
Aortice stenosis is usally degeneration and will occur usually in the 7 - 8 decades of life where the leaflets become more scarred and fused and sometimes may also lead to regurgitation as well
