Valvular heart disease
Definition
Disease of the heart valves. Go figure.
Epidemiology
I couldn't find anything good on epidemiology, just assume that everybody has valvular heart disease.
Pathophysiology
Essentially, two things can happen to heart valves: stenosis (narrowing) or regurgitation (not shutting properly). Because there are two types of defect and four valves you get the following:
Valve involved | Stenosis | Regurgitation |
Aortic valve | Aortic stenosis | Aortic regurgitation |
Mitral valve | Mitral stenosis | Mitral regurgitation |
Tricuspid valve | Tricuspid stenosis | Tricuspid regurgitation |
Pulmonary valve | Pulmonary stenosis | Pulmonary regurgitation |
Valve failure is mostly a degenerative thing. Most people have some regurgitation naturally but this gets worse over time and in some people this results in disease. Stenosis is caused usually by valve calcification and again is a natural part of aging.
Murmurs
The main signs of valvular heart disease are murmurs. You need to be able to (at least theoretically) figure out which one's which. This means that when in the written exam and you read 'end-diastolic murmur' you should know what it means. There are other signs specific to the affected heart valve.
Mitral stenosis
- Clinical features - mid-diastolic murmur, dyspnoea, fatigue, palpitations, chest pain, systemic emboli, haemoptysis, chronic bronchitis
- Investigations - ECG: AF, P mitrale (M-shaped P wave due to bulky left atrium), right ventricular hypertrophy; CXR: left atrial enlargement, pulmonary oedema, mitral valve calcification; echocardiography: this is diagnostic.
- Treatment - rate control of AF is crucial; warfarin for anticoagulation; diuretics to reduced preload and lung congestion. If these fail, surgery (valvuloplasty, valvotomy or replacement and will require prophylaxis for endocarditis).
- Complications - pulmonary hypertension, emboli, dysphagia, hoarseness
Mitral regurgitation
- Clinical features - pansystolic murmur, dyspnoea, fatigue, palpitations
- Investigations - ECG: AF +/- P-mitrale (M shaped P wave due to left atrial hypertrophy), left heart hypertrophy (both ventricle and atrium); CXR: big left heart, pulmonary oedema; Echocardiogram: assess LV function, Doppler to assess regurgitant jet; Cardiac catherisation: confirm diagnosis, exclude other disease, assess CAD.
- Management - if fast AF control rate; anticoagulate if history of embolism, AF, prosthetic valve, mitral stenosis; diuretics; surgery last-line for repair or replacement (use antibiotics prophylaxis for endocarditis).
Aortic stenosis
- Clinical features - ejection systolic murmur, angina, dyspnoea, dizziness, syncope, systemic emboli in endocarditis, CCF, sudden death; slow rising pulse, narrowed pulse pressure (low gap between systolic and diastolic BPs), left ventricular heave, aortic thrill.
- Investigations - ECG: P mitrale (M shaped P wave due to left atrial hypertrophy), left ventricular hypertrophy, left axis deviation, poor R wave progression, LBBB or complete heart block; CXR: left ventricular hypertrophy, calcified valve, dilatation of ascending aorta. Echo: diagnostic with Doppler to assess severity.
- Management - Basically, replacement or repair. Prognosis with symptoms is poor (2-3 year survival).
Aortic regurgitation
- Clinical features - early diastolic murmur, dyspnoea, palpitations, heart failure, collapsing pulse, wide pulse pressure (big difference between SBP and DBP), displaced apex beat, carotid pulsation (Corrigan's sign), head nodding (de Musset's sign), capillary pulsations in nail bed (Quincke's sign), femoral diastolic murmur due to backflow (Duroziez's sign). Man that is a lot of stupid eponymous signs.
- Investigations - ECG: left ventricular hypertrophy; CXR: cardiomegaly, dilated ascending aorta, pulmonary oedema; echo: diagnostic; catheterisation: to assess severity and health of aortic root.
- Management - indications for surgery: worsening symptoms, enlarging heart (CXR, ECG), ECG deterioration, endocarditis.