Murmurs Flashcards
normal heart sounds are caused. by
closure of heart valves
first heart sound (S1) is caused by
caused by the closure of the mitral and tricuspid valves
it marks the start of ventricular systole
a peripheral pulse is felt at the same time (or shortly after)
second heart sound (S2) is caused by
the closure of the aortic and pulmonary valves
marks the end of ventricular systole and the start of diastole
the pulmonary valve may close just after the aortic valve
split S2
S2 may not always be heard as one discrete sound but may be muffled or have two discrete sounds
due to closure of the pulmonary valve just after the aortic valve
this is prolonged during inspiration, or in defects with cause more blood to be pumped out of the right ventricle
the Levine scale for grading cardiac murmurs
what is a thrill
a palpable vibration caused by turbulent blood flow through a heart valve
thrills may be felt when palpating the anterior chest wall during cardiovascular examination
what is aortic stenosis
a tightening of the aortic valve at the origin of the aorta
what murmur is heard with aortic stenosis
ejection systolic heard loudest of the aortic valve
crescendo-decrescendo quality
commonly radiates to the carotid arteries
aetiology of aortic stenosis
- calcification of the aortic valves: most common cause in developed countries, usually in elderly adults
- congenital abnormality of the aortic valve: bicuspid when it should be tricuspid) which predisposes to the development of AS as well as aortic regurgitation
- rheumatic heart disease
clinical features of aortic stenosis
ejection systolic murmur heard loudest over the aortic area
radiates to the carotid arteries
loudest on expiration. and when the patient is sitting forwards
some others:
- slow rising pulse with narrow pulse pressure
- non-displaced, having apex beat (if present indicates left ventricular hypertrophy)
- reduced or absent S2 (a sign of moderate-severe aortic stenosis)
- reverse splitting of S2: aortic valve closes after pulmonary valve (due to the longer time required for blood to exit the left ventricle)
what is mitral regurgitation
when there is backflow (regurgitation of blood from the left ventricle to the left atria (through the mitral valve) during ventricular systole
what sort of murmur is heard in mitral regurgitation
pansystolic murmur heard loudest over the mitral area and radiating to the axilla
aetiology of mitral regurgitation
mitral regurgitation can be either acute or chronic
causes include:
- infective endocarditis
- acute myocardial infarction with rupture of papillary muscles
- rheumatic heart disease
- congenital defects of the mitral valve
- cardiomyopathy
clinical features of mitral regurgitation murmur
- a pansystolic murmur heard loudest over the mitral area
- radiation of the murmur to the axilla
- loudest expiration in the left lateral decubitus position
other clinical features may include: displaced, hyperdynamic apex beat
aortic regurgitation
backflow of blood from the aorta into the left ventricle during ventricular diastole
what kind of murmur is heard in aortic regurgitation
early diastolic murmur heard loudest at the left sternal edge
aetiology of aortic regurgitation
may be acute or chronic. Chronic AR is often asymptomatic
AR can occur due to a disease process affecting the valve itself, or due to dilatation of the aortic root
diseases that may affect the valve and cause aortic regugitation
congenital bicuspid aortic valve
rheumatic heart disease
infective endocarditis
causes of aortic root dilatation which may cause aortic regurgitation
aortic dissection: can result in acute aortic regurgitation
connective tissue disease e.g. marfans
aortitis