Heart murmurs Flashcards
What is the pathophysiology of mitral stenosis?
Thickening and immobility of the valve leaflets leads to obstruction of blood flow from the left atrium to left ventricle. As a result there is an increase in left atrial pressure, pulmonary hypertension and right heart dysfunction. Atrial fibrillation is common due to the elevation of left atrial pressure and dilatation.
What are the symptoms associated with mitral stenosis?
Exertional dyspnoea which becomes progressively more severe
A cough productive of blood-tinged sputum is common, and frank haemoptysis
AF
Pulmonary oedema
Pulmonary hypertension eventually leads to right heart failure with fatigue and lower limb oedema.
What are the signs seen in mitral stenosis?
Mitral facies or malar flush occurs with severe stenosis
The pulse is low volume and may become irregular if atrial fibrillation develops
The apex beat is ‘tapping’ in quality
Auscultation at the apex reveals a loud first heart sound, an opening snap (when the mitral valve opens) in early diastole, followed by a rumbling mid- diastolic murmur.
The presence of a loud second heart sound, parasternal heave, elevated JVP, ascites and peripheral oedema indicate that pulmonary hypertension pro- ducing right ventricular overload has developed.
What are the causes of mitral regurgitation?
Rheumatic heart disease
Mitral valve prolapse
Infective endocarditis*
Ruptured chordae tendineae*
Rupture of the papillary muscle* complicating myocardial infarction
Papillary muscle dysfunction
Dilating left ventricle disease causing ‘functional’ mitral regurgitation
Hypertrophic cardiomyopathy
Rarely: systemic lupus erythematosus, Marfan’s syndrome
Ehlers–Danlos syndrome
What is the pathophysiology of mitral regurgitation?
Long-standing regurgitation produces little increase in the left atrial pressure because flow is accommodated by an enlarged left atrium. With acute mitral regurgitation there is a rise in left atrial pressure, resulting in an increase in pulmonary venous pressure and pulmonary oedema
What are the symptoms of mitral regurgitation?
Pulmonary oedema
Chronic- exertional dyspnoea, fatigue, lethargy
Later stages right heart failure also occurs
Thromboembolism is less common than in stenosis, but infective endocarditis is more common
What are the signs in mitral regurgitation?
Apex beat is displaced laterally with a diffuse thrusting character
First heart sound is soft
Pansysytolic murmur (palpated as a thrill), loudest at the apex and radiating into the axilla
Third heart sound is often present
What are the investigations for mitral regurgitation?
Chest x-ray and ECG aren’t sensitive
Doppler is used to measure the severity
What causes a prolapsing (floppy) mitral valve?
Occurs mainly in young women
Associated with Marfan’s, hyperthyroidism, rheumatic or ischaemic heart disease
What are the clinical features of a prolapsing mitral valve?
Most are asymptomatic
Atypical chest pain
Palpitations
Mid-systolic click followed by a murmur
What causes aortic stenosis?
Degeneration and calcification of a normal valve – presenting in the elderly
Calcification of a congenital bicuspid valve – presenting in middle age
Rheumatic heart disease
What is the pathophysiology of aortic stenosis?
Obstruction to left ventricular emptying results in left ventricular hypertrophy. In turn this results in increased myocardial oxygen demand, relative ischaemia of the myocardium and consequent angina and arrhythmias
What are the symptoms of aortic stenosis?
Usually non until moderately severe Angina Exertional syncope Dyspnoea Ventricular arrhythmias
What are the signs in aortic stenosis?
Carotid pulse is slow rising
Thrusting apex beat
Harsh systolic ejection murmur (palpated as a thrill)
Second heart sound may become soft when the valve becomes immobile
What causes acute aortic regurgitation?
Infective endocarditis Acute rheumatic fever Dissection of aorta Ruptured sinus or valsalva aneurysm Failure of prosthetic valve
