CVS: Valvular Heart Disease Flashcards
Outline the pathophysiology of mitral stenosis
Rheumatic heart disease = autoimmune attack on the mitral valve produces thickening of the valve leaflets
Valve progressively narrows = resting diastolic mitral valve gradient, and hence left atrial pressure, increases = transudation of fluid into the lung interstitium = dyspnoea at rest or with minimal exertion
Haemoptysis = bronchial veins rupture
LA dilatation increases the risk for atrial fibrillation and subsequent thromboembolism
What is the aetiology of mitral stenosis?
Rheumatic
Congenital
Malignant carcinoid
Prosthetic valve
What are the symptoms and signs of mitral stenosis?
When <2cm
Dyspnoea
Fatigue
Palpitations
Haemoptysis
Malar flush
Low volume pulse
Auscultation: loud S1, opening snap, rumbling mid-diastolic murmur (best heard on expiration)
What investigations should be performed when mitral stenosis is suspected?
ECG = AF, RVH
CXR = left atrial enlargement, pulmonary oedema, mitral valve calcification
ECHO
Doppler ECHO
How should mitral stenosis be managed?
AF rate control and anticoag
Diuretics = decrease preload and pulmonary congestion
Balloon valvuloplasty
Valve replacement
What are the possible complications of mitral stenosis?
Pulmonary HTN
Emboli
Pressure form large LA on local structures (recurrent laryngeal N, oesophagus)
Discuss the pathophysiology of mitral regurgitation
Abnormal reversal of blood flow from the LV to the left atrium LA
MR results in volume overload of the LA and LV = chronic LV volume overload in MR results in increasing annular dilatation that leads to cascading effect and further increases in MR
What are the causes of mitral regurgitation?
LV dilation
Annular calcification
Rheumatic fever
Infective endocarditis
Mitral valve prolapse
Ruptured chordae tendinae
Papillary muscle dysfunction
Cardiomyopathy
Congenital
Outline the symptoms and signs of mitral regurgitation
Dyspnoea
Fatigue
Palpitations
AF
Displaced apex
RV heave
Pansystolic murmur at apex radiating to axilla
What investigations should be performed when mitral regurgitation is suspected?
ECG = AF
CXR = enlarged LA + LV, mitral valve calcification, pulmonary oedema
ECHO
Doppler ECHO
How should mitral regurgitation be managed?
AF rate control and anticoag
Diuretics
Surgery to repair or replace the valve
What are the possible complications from mitral regurgitation?
HF
Pulmonary HTN
Outline the pathophysiology of aortic stenosis
Senile degeneration of the valve
Outflow obstruction = increase in LV systolic pressure = compensatory mechanism to normalize LV wall stress, LV wall thickness increases by parallel replication of sarcomeres, producing concentric hypertrophy
Eventually, LV end-diastolic pressure rises = increase in pulmonary capillary arterial pressures and a decrease in CO due to diastolic dysfunction
Contractility of the myocardium may also diminish = decrease in CO due to systolic dysfunction, ultimately HF develops.
What are the causes of aortic stenosis?
Senile calcification
Congenital = bicuspid valve
Rheumatic heart disease
What is the classic triad of symptoms of aortic stenosis
- Chest pain: Angina pectoris in patients with aortic stenosis is typically precipitated by exertion and relieved by rest
- Heart failure: Symptoms include paroxysmal nocturnal dyspnoea, orthopnoea, dyspnoea on exertion, and SOB
- Syncope: Often occurs upon exertion when systemic vasodilatation in the presence of a fixed forward stroke volume causes the arterial systolic blood pressure to decline
What investigations should be performed when aortic stenosis is suspected?
ECG = LVH with strain pattern, poor R wave progression, LBBB or complete AV block
CXR = LVH, calcified aortic valve, post stenotic dilation of ascending aorta
ECHO
Doppler ECHO
How is aortic stenosis managed?
Valve replacement
Percutaneous valvuloplasty/replacement
What are the possible complications of aortic stenosis?
HF
Sudden death
Describe the pathophysiology of aortic regurgitation
Diastolic reflux through the aortic valve can lead to LV volume overload = increase in systolic stroke volume and low diastolic aortic pressure produces an increased pulse pressure
Acute = LV does not have enough time to dilate in response to the sudden increase in volume = increase in pulmonary venous pressure
Chronic = LV enlargement and eccentric hypertrophy
What are the causes of aortic regurgitation
Infective endocarditis
Ascending aortic dissection
Chest trauma
Congenital
CT disorder
Rheumatic fever
RA
SLE
HTN
What are the symptoms and signs of aortic regurgitation?
Exertional dyspnoea
Orthopnoea
Paroxysmal nocturnal dyspnoea
Palpitations
Angina
Syncope
Collapsing pulse
Wide pulse pressure
High pitched early diastolic murmur
Carotid pulsation
Head nodding with each beat
What investigations should be performed when aortic regurgitation is suspected?
ECG = LVH
CXR = cardiomegaly, dilated ascending aorta, pulmonary oedema
ECHO
Cardiac catheterisation
How is aortic regurgitation managed?
ACEi = reduce systolic HTN
ECHO every 6-12m to monitor
Valve replacement
What are the possible complications of aortic regurgitation?
HF
Sudden death
Arrhythmias
