General cardiac circulation and murmurs

Question 1

when does a fetal heart beat begin?

Answer 1

4th week of gestation

Question 2

4 major functions of placenta

Answer 2

gas exchange (lungs)
nutrition (GI tract, liver, kidneys)
waste removal (liver, kidneys)
fluid and electrolyte balance (kidneys)

Question 3

function of shunts in fetal circulation

Answer 3

blood bypasses certain areas to make oxygen and nutrition delivery and waste removal more efficient

Question 4

Placenta (circulatory shunt)

Answer 4

blood from iliac arteries form paired umbilical arteries
shunts blood away from lower extremities and GI and into the placenta
deoxygenated blood

Question 5

Ductus venosus (circulatory shunt)

Answer 5

shunts blood from umbilical vein to the IVC directly, bypassing the liver
placenta –> umbilical vein –> ductus venosus –> IVC –> right atrium
oxygenated blood

Question 6

foramen ovale (circulatory shunt)

Answer 6

shunts blood from right atrium to left atrium
~1/2 of blood that comes from IVC crosses the right-to-left shunt
allows oxygenated blood to bypass the lungs to be used in systemic circulation (placenta does oxygen transfer so doesn’t need to go to lungs)

Question 7

Ductus arteriosus (circulatory shunt)

Answer 7

shunts blood from pulmonary artery to aorta
right-to-left shunt
remains open due to relaxation facilitated by PROSTAGLANDINS
large portion of blood entering pulmonary artery shunts to aorta > 80%

Question 8

In cardiac septa development, what can lead to ASD

Answer 8

septa primum, septa secundum, foramen secundum

Question 9

in cardiac septa development, what can lead to VSD

Answer 9

membranous septum most commonly

could also be interventricular muscular septum

Question 10

Anatomic changes

Answer 10

Ductus venosus –> ligamentum venosum
Umbilical arteries –> medial umbilical ligament/fold
Umbilical vein –> ligamentum teres (runs w falciform ligament)
Ductus arteriosus –> ligamentum arteriosum

Question 11

Stenotic murmur

Answer 11

valves that should be open but are partially closed

Question 12

regurgitation murmor

Answer 12

valves that should be closed but aren’t

Question 13

what valves should be open during systole (ventricular contraction)?

Answer 13

pulmonary and aorta

Question 14

what valves should be closed during systole (ventricular contraction)?

Answer 14

mitral and tricuspid

Question 15

what valves should be open during diastole (ventricular relaxation)?

Answer 15

mitral and tricuspid

Question 16

what valves should be closed during diastole (ventricular relaxation)?

Answer 16

pulmonary and aortic

Question 17

Why is PDA a continuous murmur?

Answer 17

there is always some blood in that area (pulmonary and aorta)

Question 18

Preload

Answer 18

end diastolic volume - volume of blood in the ventricles prior to ejection

Question 19

Afterload

Answer 19

resistance that must be overcome for ventricles to eject blood

Question 20

Pressures

Answer 20

LV pressure > RV pressure
Aortic pressure > Pulmonary artery pressure
LA pressure > RA pressure

Question 21

Valsalva

Answer 21

decreases venous return, decreases end diastolic volume, decreases stroke volume

Question 22

Valsalva effects on pulmonic and aortic stenosis

Answer 22

decrease in murmurs due to decrease in volume of flow from ventricles through valves

Question 23

valsalva effects on VSD sound

Answer 23

decrease in volume of flow leads to decrease of shunting

Question 24

Valsalva effects on hypertrophic cardiomyopathy

Answer 24

decrease end diastolic volume leads to decreased stretching leads to decrease in LV outflow tract size which leads to increased intensity of murmur

Question 25

Increase in venous return equals

Answer 25

increase in preload

Question 26

increase in SVR (systemic vascular resistance) equals

Answer 26

increase in afterload

Question 27

How does squatting affect mitral regurgitation

Answer 27

increase after load and preload which leads to an increase in back flow pressure which leads to an increase flow across regurgitant valve

Question 28

how does squatting affect VSD

Answer 28

increase preload and after load which leads to increased shunting

Question 29

how does squatting affect aortic regurgitation

Answer 29

increased after load which leads to increased regurgitation during diastole

Question 30

how does squatting affect hypertrophic cardiomyopathy

Answer 30

increased end diastolic volume which leads to stretching of the ventricle which causes a larger outflow tract which leads to decrease outflow stenosis

Question 31

What does inspiration/expiration NOT affect?

Answer 31

mitral valve prolapse and HOCM

Question 32

PDA murmur

Answer 32

continuous machinery like murmur at left upper sternal border through systole and diastole

Question 33

PDA complications

Answer 33

increased flow to lungs through pulmonary arteries leads to increased venous return to LA and LV which leads to increased heart workload increased RV pressure over time

Question 34

Murmur of ASD

Answer 34

crescendo-decrescendo systolic ejection murmur wide fixed splitting of S2 both are due to increased pressure/volume in pulmonic

Question 35

VSD murmur

Answer 35

loud, harsh, holosystolic murmur | systolic thrill left lower sternal border with radiation to neck

Question 36

why may a VSD not be audible on a neonate?

Answer 36

pressures are similar in a neonate

Question 37

VSD complications

Answer 37

*shunting occurs during systole when RV is contracting* increased blood volume into pulmonary artery which leads to increased PVR which leads to increased venous return to LA and LV which causes hypertrophy of LV

Question 38

What will you see on chest x-ray on Eisenmenger?

Answer 38

enlarged pulmonary artery

Question 39

Murmur of coarctation of aorta

Answer 39

systolic ejection murmur due to rapid blood flow through narrowing

Question 40

coarctation of aorta on chest x-ray

Answer 40

3's sign | rib notching

Question 41

4 main defects in tetralogy of fallot

Answer 41

VSD pulmonary stenosis overriding aorta RV hypertrophy

Question 42

Chest x-ray tetralogy of fallot

Answer 42

``` Boot shaped right aortic notch upturned apex due to RVH hyperinflation of lungs decreased pulmonary vasculature ```

Question 43

pAtria > pVentricles -->

Answer 43

mitral and tricuspid are open during mid-late ventricular diastole

Question 44

pArterial < pVentricles -->

Answer 44

aorta and pulmonary valves are open during ventricular systole