Heart Sounds Flashcards
what causes S1?
closure of the mitral and tricuspid valves
what causes S2?
aortic and pulmonary valve closure
what causes a soft S1?
- long PR
- mitral regurgitation
what causes a loud S1?
mitral stenosis
what causes a soft S2?
aortic stenosis
what can happen to S2 on inspiration?
splitting = normal
what causes S3?
diastolic filling of the ventricle
at what age is S3 normal?
<30 years old
may persist in women up to 50 years old
what conditions can cause S3?
- left ventricular failure (e.g. dilated cardiomyopathy)
- constrictive pericarditis
- mitral regurgitation
what is a pericardial knock and what condition is it associated with?
S3 (third heart sound)
associated with constrictive pericarditis
what conditions can cause S4?
- aortic stenosis
- HOCM
- hypertension
what causes S4?
atrial contraction against a stiff ventricle
what feature on an ECG does S4 coincide with?
P wave
what causes a double apical impulse in HOCM?
palpable S4
where is pulmonary valve heard best?
- left 2nd intercostal space
- upper sternal border
describe the flow blood through the heart
vena cava –> right atrium -> tricuspid valve -> right ventricle -> pulmonary valve –> pulmonary arteries –> lungs –> pulmonary vein –> left atrium -> mitral valve -> left ventricle -> aortic valve –> aorta –> rest of the body
