Mitral valve disease Flashcards
What is mitral regurgitation?
Mitral regurgitation (MR), also known as mitral insufficiency, occurs when blood leaks back through the mitral valve during systole.
How common is mitral regurgitation?
It is the second most common valve disease after aortic stenosis.
What are the consequences of mitral regurgitation?
Regurgitation leads to a less efficient heart, as less blood is pumped through the body with each contraction.
What are the risk factors for mitral regurgitation?
Risk factors include female sex, lower body mass, age, renal dysfunction, prior myocardial infarction, prior mitral stenosis or valve prolapse, and collagen disorders such as Marfan’s Syndrome and Ehlers-Danlos syndrome.
What are some causes of mitral regurgitation?
Causes include coronary artery disease, mitral valve prolapse, infective endocarditis, rheumatic fever, and congenital factors.
What symptoms are associated with mitral regurgitation?
Most patients are asymptomatic; however, symptoms may include fatigue, shortness of breath, and edema due to left ventricle failure, arrhythmias, or pulmonary hypertension.
What signs can be observed in mitral regurgitation?
A pansystolic murmur described as ‘blowing’ is typically heard at the apex and radiates into the axilla. Severe MR may cause a widely split S2.
What investigations are used for diagnosing mitral regurgitation?
Investigations include ECG (which may show a broad P wave), chest x-ray (showing cardiomegaly), and echocardiography (crucial for diagnosis and assessing severity).
What are the treatment options for mitral regurgitation?
Treatment options include medical management with nitrates, diuretics, positive inotropes, and surgery in acute severe cases. Repair is preferred over replacement when possible.
What is mitral stenosis?
Mitral stenosis describes the obstruction of blood flow across the mitral valve from the left atrium to the left ventricle.
What are the consequences of mitral stenosis?
It leads to increases in pressure within the left atrium, pulmonary vasculature, and right side of the heart.
What are the primary causes of mitral stenosis?
The primary cause is rheumatic fever.
What are some rarer causes of mitral stenosis?
Rarer causes include mucopolysaccharidoses, carcinoid, and endocardial fibroelastosis.
What are common features of mitral stenosis?
Common features include dyspnoea, pulmonary venous hypertension, haemoptysis, mid-late diastolic murmur, loud S1, opening snap, low volume pulse, malar flush, and atrial fibrillation.
What does a mid-late diastolic murmur indicate?
It is best heard in expiration and indicates mitral valve leaflets are still mobile.
What are features of severe mitral stenosis?
In severe MS, the length of the murmur increases and the opening snap becomes closer to S2.
What might a chest x-ray show in a patient with mitral stenosis?
Left atrial enlargement may be seen.
What is the normal cross-sectional area of the mitral valve?
The normal cross-sectional area is 4-6 sq cm. A ‘tight’ mitral stenosis implies a cross-sectional area of < 1 sq cm.
What is the management for patients with atrial fibrillation and mitral stenosis?
Patients require anticoagulation, with warfarin still recommended for moderate/severe MS.
What is the management for asymptomatic patients with mitral stenosis?
They are monitored with regular echocardiograms, and percutaneous/surgical management is generally not recommended.
What are the treatment options for symptomatic patients with mitral stenosis?
Treatment options include percutaneous mitral balloon valvotomy and mitral valve surgery (commissurotomy or valve replacement).
What is mitral valve prolapse?
Mitral valve prolapse is common, occurring in around 5-10% of the population. It is usually idiopathic but may be associated with a wide variety of cardiovascular disease and other conditions.
What are some associations of mitral valve prolapse?
Associations include congenital heart disease (PDA, ASD), cardiomyopathy, Turner’s syndrome, Marfan’s syndrome, Fragile X, osteogenesis imperfecta, pseudoxanthoma elasticum, Wolff-Parkinson White syndrome, long-QT syndrome, Ehlers-Danlos Syndrome, and polycystic kidney disease.
What are the features of mitral valve prolapse?
Patients may complain of atypical chest pain or palpitations. Features include a mid-systolic click (occurs later if patient squatting) and a late systolic murmur (longer if patient standing).
What are the complications of mitral valve prolapse?
Complications include mitral regurgitation, arrhythmias (including long QT), emboli, and sudden death.
What are the most common heart valves that need replacing?
The most common valves which need replacing are the aortic and mitral valve.
What are the two main options for heart valve replacement?
The two main options for replacement are biological (bioprosthetic) or mechanical.
What is the origin of biological (bioprosthetic) valves?
Biological (bioprosthetic) valves are usually bovine or porcine in origin.
What is a major disadvantage of biological (bioprosthetic) valves?
The major disadvantage is structural deterioration and calcification over time.
Which patients typically receive bioprosthetic valves?
Most older patients (> 65 years for aortic valves and > 70 years for mitral valves) receive a bioprosthetic valve.
Is long-term anticoagulation usually needed for bioprosthetic valves?
Long-term anticoagulation is not usually needed for bioprosthetic valves.
What anticoagulant may be given for the first 3 months for bioprosthetic valves?
Warfarin may be given for the first 3 months depending on patient factors.
What is given long-term for patients with bioprosthetic valves?
Low-dose aspirin is given long-term.
What is the most common type of mechanical valve now implanted?
The most common type now implanted is the bileaflet valve.
What is a major disadvantage of mechanical valves?
The major disadvantage is the increased risk of thrombosis, meaning long-term anticoagulation is needed.
What anticoagulant is preferred for patients with mechanical heart valves?
Warfarin is still used in preference to DOACs for patients with mechanical heart valves.
When is aspirin normally given for patients with mechanical valves?
Following the 2017 European Society of Cardiology guidelines, aspirin is only normally given in addition if there is an additional indication, e.g. ischaemic heart disease.
What is the target INR for aortic valves?
The target INR for aortic valves is 3.0.
What is the target INR for mitral valves?
The target INR for mitral valves is 3.5.
Are antibiotics recommended for common procedures to prevent endocarditis?
Following the 2008 NICE guidelines for prophylaxis of endocarditis, antibiotics are no longer recommended for common procedures such as dental work.
