Physiology Lecture 3 -- Heart Sounds Flashcards
Where to auscultate to hear loudest S1
Heart apex (tip of left ventricle)
Where to auscultate to hear loudest S2
Base of heart (aortic area)
What is dP/dT
Slope of the left ventricular pressure curve
What does the intensity of S1 depend on?
The mitral valve leaf locations when LVP and LAP juxtapose
Effect of dP/dT on intensity of S1
Shallow slope = slow P rise = quieter S1 (think of it as slowly closing a door versus slamming it shut, if the slope was steeper)
What condition can produce a louder than usual S1?
Left atrial pressure higher than normal due to mitral stenosis (obstruction to mitral inflow)
Physiological splitting of S2 cause
Inspiration causes the pulmonary valve to close a bit later than the aortic valve, causing a split in S2 due to a shift of the A2 P2 interval
Define mitral stenosis
Mitral valve does not open properly since it’s shaped more like two hockey sticks (U) than a W = valve parachutes open
Assume no calcification
When can opening sounds be heard?
Just after S2
Common cause of mitral stenosis
Rheumatic fever –> rheumatic heart disease –> rheumatic mitral stenosis
Increased severity of mitral stenosis effect on quality of opening sounds
Increase left atrial pressure causes a decrease of A2 - opening sound interval (isovolumetric relaxation) = harder to differentiate between the two
What does S3 imply
Volume overload
What does S4 imply
Pressure overload
2 conditions that can lead to S3’s
Mitral regurgitation
Constrictive pericarditis
Describe the quality of the sound produced from a heart with constrictive pericarditis
Pericardial knock = really strong S3 that is louder than both S1 and S2
What causes S4
Any condition that makes the heart stiff (i.e. hypertensive ventricle, hypertrophic cardiomyopathy, aortic stenosis)
Quality of sound produced by a hypertensive ventricle
S4 gallop
S4 position in heart cycleq
Late diastole coincident with atrial kick
Define hypertrophic cardiomyopathy
When one is born with an abnormally thick heart
What is the most common cause of sudden cardiac death in the young
Hypertrophic cardiomyopathy
Why would ejection sounds occur
Valve is opening or closing incompletely
2 examples of causes for ejection sounds
Bicuspid aortic valve
Aortic regurgitation
Location of ejectoin sound from bicuspid aortic valve in heart cycle
After isovolumetric contraction (early systole)
Location of ejection sound heard from aortic regurgitation in heart cycle
When blood is returning from aorta in diastole
Describe the heart ejection sound produced by aortic regurgitation
Early diastolic murmur that sounds like a blowing sound after S2
4 types of systolic murmurs
Early systolic
Holosystolic
Mid-systolic
Late-systolic
4 types of diastolic murmurs
Early diastolic
Mid-diastolic and presystolic
S3 rumble
Austin Flat Murmurs
What is a continuous murmur?
A murmru that occurs all throughout systole AND diastole
Describe an early systolic murmur
Like a washing machine
Example of an early diastolic murmur
Aortic regurgitation
Example of a mid diastolic or pre systolic murmur
Mitral stenosis
Examples of S3 rumbles
Mitral regurgitation
Septal defect
Mitral stenosis
What is a potential reason for continuous heart murmurs
Patent ductus arteriosis
