heart sounds and valves Flashcards
first heart sound S1 is caused by
closure of the mitral and tricuspid valves
soft if long PR or mitral regurgitation
loud in mitral stenosis
second heart sound (S2) is due
aortic and pulmonary valve closure
soft in aortic stenosis
splitting during inspiration is normal
S3 (third heart sound) caused by
diastolic filling of the ventricle
considered normal if < 30 years old (may persist in women up to 50 years old)
heard in left ventricular failure (e.g. dilated cardiomyopathy), constrictive pericarditis (called a pericardial knock) and mitral regurgitation
S4 fourth heart sound heard in
and caused bu
aortic stenosis, HOCM, hypertension
caused by forceful atrial contraction against a stiff ventricle
therefore coincides with the P wave on ECG
in HOCM a double apical impulse may be felt as a result of a palpable S4
where do you find the pulmonary valve
Left second intercostal space, at the upper sternal border
where do you find the aortic valve
Right second intercostal space, at the upper sternal border
where do you find the mitral valve
Left fifth intercostal space, just medial to mid clavicular line
where do you find the tricuspid valve
Left fourth intercostal space, at the lower left sternal border
are left sided murmurs louder on expiration or inspiration
expiration and right sided murmurs are louder on inspiration due to increased venous return to the heart.
where could you listen to identify a mitral regurgitation a
axilla - mitral stenosis does not radiate
Broadly speaking, diastolic murmurs can be heard better with a position change, whilst systolic murmurs ( aortic stenosis or mitral regurgitation tend to radiate so listening in a different anatomical landmark can help to make distinguish them
For example, an aortic stenosis can radiate to the carotids, whereas an aortic regurgitation may be heard better with the patient leant forward
what are the diastolic murmurs
aortic regurgitation and mitral stenosis
why does the murmur occur in aortic regurgitation
The murmur heard in aortic regurgitation occurs early in diastole due to the backflow of blood from the aorta into the left ventricle through an incompetent aortic valve.
features of aortic regurgitation
early diastolic murmur: intensity of the murmur is increased by the handgrip manoeuvre( squeeze hand)
collapsing pulse
wide pulse pressure
Quincke’s sign (nailbed pulsation)
De Musset’s sign (head bobbing)
mid-diastolic Austin-Flint murmur in severe AR - due to partial closure of the anterior mitral valve cusps caused by the regurgitation streams
handgrip manœuvre increases what
aferload
