Physiology Lecture 3 -- Heart Sounds

Question 1

Where to auscultate to hear loudest S1

Answer 1

Heart apex (tip of left ventricle)

Question 2

Where to auscultate to hear loudest S2

Answer 2

Base of heart (aortic area)

Question 3

What is dP/dT

Answer 3

Slope of the left ventricular pressure curve

Question 4

What does the intensity of S1 depend on?

Answer 4

The mitral valve leaf locations when LVP and LAP juxtapose

Question 5

Effect of dP/dT on intensity of S1

Answer 5

Shallow slope = slow P rise = quieter S1 (think of it as slowly closing a door versus slamming it shut, if the slope was steeper)

Question 6

What condition can produce a louder than usual S1?

Answer 6

Left atrial pressure higher than normal due to mitral stenosis (obstruction to mitral inflow)

Question 7

Physiological splitting of S2 cause

Answer 7

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

Question 8

Define mitral stenosis

Answer 8

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

Question 9

When can opening sounds be heard?

Answer 9

Just after S2

Question 10

Common cause of mitral stenosis

Answer 10

Rheumatic fever –> rheumatic heart disease –> rheumatic mitral stenosis

Question 11

Increased severity of mitral stenosis effect on quality of opening sounds

Answer 11

Increase left atrial pressure causes a decrease of A2 - opening sound interval (isovolumetric relaxation) = harder to differentiate between the two

Question 12

What does S3 imply

Answer 12

Volume overload

Question 13

What does S4 imply

Answer 13

Pressure overload

Question 14

2 conditions that can lead to S3’s

Answer 14

Mitral regurgitation

Constrictive pericarditis

Question 15

Describe the quality of the sound produced from a heart with constrictive pericarditis

Answer 15

Pericardial knock = really strong S3 that is louder than both S1 and S2

Question 16

What causes S4

Answer 16

Any condition that makes the heart stiff (i.e. hypertensive ventricle, hypertrophic cardiomyopathy, aortic stenosis)

Question 17

Quality of sound produced by a hypertensive ventricle

Answer 17

S4 gallop

Question 18

S4 position in heart cycleq

Answer 18

Late diastole coincident with atrial kick

Question 19

Define hypertrophic cardiomyopathy

Answer 19

When one is born with an abnormally thick heart

Question 20

What is the most common cause of sudden cardiac death in the young

Answer 20

Hypertrophic cardiomyopathy

Question 21

Why would ejection sounds occur

Answer 21

Valve is opening or closing incompletely

Question 22

2 examples of causes for ejection sounds

Answer 22

Bicuspid aortic valve

Aortic regurgitation

Question 23

Location of ejectoin sound from bicuspid aortic valve in heart cycle

Answer 23

After isovolumetric contraction (early systole)

Question 24

Location of ejection sound heard from aortic regurgitation in heart cycle

Answer 24

When blood is returning from aorta in diastole

Question 25

Describe the heart ejection sound produced by aortic regurgitation

Answer 25

Early diastolic murmur that sounds like a blowing sound after S2

Question 26

4 types of systolic murmurs

Answer 26

Early systolic
Holosystolic
Mid-systolic
Late-systolic

Question 27

4 types of diastolic murmurs

Answer 27

Early diastolic
Mid-diastolic and presystolic
S3 rumble
Austin Flat Murmurs

Question 28

What is a continuous murmur?

Answer 28

A murmru that occurs all throughout systole AND diastole

Question 29

Describe an early systolic murmur

Answer 29

Like a washing machine

Question 30

Example of an early diastolic murmur

Answer 30

Aortic regurgitation

Question 31

Example of a mid diastolic or pre systolic murmur

Answer 31

Mitral stenosis

Question 32

Examples of S3 rumbles

Answer 32

Mitral regurgitation
Septal defect
Mitral stenosis

Question 33

What is a potential reason for continuous heart murmurs

Answer 33

Patent ductus arteriosis