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
clinical features of aortic regurgitation
decrescendo early diastolic murmur
heard loudest at the left sternal edge (the direction that turbulent blood flows) sometimes heard loudest over the aortic area
Austin Flint murmur
other clinical features may include:
- collapsing pulse (a water hammer pulse)
- displaced, hyperdynamic apex beat
austin flint murmur
a low pitched rumbling mid-diastolic murmur heard best at the apex. this is caused by the regurgitated blood through the aortic valve mixing with blood from the left atrium, during atrial contraction. sign of severe aortic regurgitation
what is mitral stenosis
narrowing of the mitral valve, which results in decreased filling of the left ventricle during systole and increased left atrial pressure (due to incomplete left atrial emptying)
mitral stenosis is associated with a low-pitched, rumbling, mid-diastolic murmur heard loudest over the apex
what kind of murmur is heard with mitral stenosis
mitral stenosis is associated with a low-pitched, rumbling, mid-diastolic murmur heard loudest over the apex
aetiology of mitral stenosis
rheumatic heart disease is the most common cause of mitral stenosis
other rarer causes include:
- congenital
- left atrial myxoma
- connective tissue disorders
- mucopolysaaccharidosis
clinical features of mitral stenosis murmur
low-pitched, rumbling mid-diastolic murmur with an opening click (click heard in mid-diastole which the mitral valve opens)
murmur is heard loudest over the apex
loudest in left lateral decubitus position on expiration
other clinical features of mitral stenosis include:
- a low-volume pulse which may be irregularly irregular (atrial fibrillation is common in mitral stenosis
- loud first heart sound with tapping apex beat (due to palpable closing of mitral valve)
- a malar flush (plum-red discolouration of the cheeks)
what is mitral valve prolapse
occurs when the mitral valve leaflets prolapse into the left atrium during systole
what murmur is associated with mitral valve prolapse
associated with a combination of a mid-systolic click and a mid to late-systolic murmur
aetiology of mitral valve prolapse
most common valvular abnormality with a prevalence of approximately 5%
exact underlying cause is unknown
types of mitral valve prolapse
- primary (classic) mitral valve prolapse is when prolapse is caused by a myxomatous degeneration of the mitral valve and is associated with connective tissue disease
- secondary (non-classic) mitral valve prolapse occurs when a normal valve prolapses
clinical features of mitral valve prolapse murmur
mid-systolic click (prolapse of the mitral valve into the left atrium)
followed by a mid or late-systolic murmur
heard loudest at the apex
loudest in expiration
what is tricuspid regurgitation
occurs when there is backflow of blood from the right ventricle into the right atrium during ventricular systole
this causes an increase in right atrial pressure and elevated venous pressures
what murmur is heard in tricuspid regurgitation
associated with a pansystolic murmur that is heard loudest over the tricuspid region
aetiology of tricuspid regurgitation
- right ventricular dilation (e.g. secondaary to pulmonary stenosis or pulmonary hypertension)
- rheumatic fever
- infective endocarditis (IV drug users are at high risk of endocarditis affecting the tricuspid valve)
- carcinoid syndrome
- congenital (e.g. atrial septal defect, Ebstein anomaly)
Ebstein anomaly
congenital isolated tricuspid regurgitation
an abnormal attachment of tricuspid valve leaflets which causes the tricuspid valve to displace downwards into the right ventricle
clinical features of tricuspid regurgitation murmur
pansystolic murmur
heard loudest over the tricuspid region
loudest during inspiration
other clinical features
- large v-waves visible in the jugular veins: caused by the right atrial filling of blood gainst a closed tricuspid valve
- visible/palpable hepatic pulsations
- signs of right sided heart failure: right ventricualr heave, peripheral oedema, hepatomegaly, ascites
what is pulmonary stenosis
narrowing of the pulmonary valve
it is commonly associated with other congenital heart defects
what murmur is heard in pulmonary stenosis
ejection systolic murmur heard loudest over pulmonary area
aetiology of pulmonary stenosis
- congenital: turner’s, noonan’s, and williams syndromes. tetralogy of fallot (pulmonary stenosis, right ventricular hypertrophy, ventricular septal defect and an overriding aorta
- rheumatic fever
- carcinoid syndrome
clinical features of pulmonary stenosis
- ejection systolic murmur heard loudest over the pulmonary area
- loudest during inspiration
- rediates to left shoullder/left infraventricular region
in severe pulmonary stenosis, the murmur is longer and may obscure the sound of A2
other clinical features of pulmonary stenosis may include:
- prominent ‘a waves’ in the jugular veins
- widely split S2
- P2 may be soft and inaudible
- right ventricular dilatation can lead to a right ventricular heave, tricuspid regurgitation and peripheral signs of right-sided heart failure (e.g. peripheral oedema, ascites etc)
why does pulmonary stenosis cause a widely split S2
blood from the ventricles takes longer to pass through a narrow pulmonary valve, so pulmonary valve closure occurs much later than aortic valve closure
what is pulmonary regurgitation
when there is backflow of blood from the pulmonary artery into the right ventricle during ventricular diastole
pulmonary regurgitation is rare
aetiology of pulmonary regurgitation
causes of pulmonary regurgitation
- pulmonary hypertension
- infective endocarditis
- congenital valvular disease
clinical features of pulmonary regurgitation
usually asymptomatic
- early decrescendo murmur heard loudest over the left sternal edge
loudest during inspiration
usually due to pulmonary hypertension: known as a graham steell murmur when associated with mitral stenosis
what kind of murmur is pulmonary regurgitation associated with
early decrescendo murmur heard loudest over the left sternal edge
what is tricuspid stenosis
narrowing of the tricuspid valve
what kind of murmur is tricuspid stenosis associated with
a soft diastolic murmur heard loudest at 3rd-4th intercostal space at the left sternal edge
aetiology of tricuspid stenosis
causes include:
- rheumatic fever (most common)
- congenital disease
- infective endocarditis
clinical features of tricuspid stenosis
- mid-diastolic murmur (rarely audible)
- loudest at 3rd-4th intercostal space at the left sternal edge
- loudest during inspiration
other clinical features:
- raised JVP with giant ‘a waves’
- peripheral oedema ascites
