Congenital heart disease

Question 1

What is the organ of respiration in the fetus?

Answer 1

the placenta

Question 2

How is the circulation arranged in the fetus?

Answer 2

parallel (adults is in series)

Question 3

Describe SVR and PVR in the fetus?

Answer 3

SVR- low
PVR- high

Question 4

What kind of shunting occurs in the fetus?

Answer 4

right-to-left shunting across the foramen ovale and ductus arteriosus

Question 5

Describe the umbilical vein and artery of the fetus.

Answer 5

one umbilical vein that carries oxygenated blood from the mother to the fetus
two umbilical arteries that carry deoxygenated blood from the fetus to the mother

Question 6

The fetal circulation is ________ dependent

Answer 6

shunt

Question 7

Shunts in the fetus are

Answer 7

beneficial in utero but can be problematic during extrauterine life

Question 8

___________ shunts blood from the right atrium to the left atrium bypassing the lungs

Answer 8

foramen ovale

Question 9

__________ shunts blood from the umbilical vein to the IVC bypassing the liver)

Answer 9

ductus venous

Question 10

________________ shunts blood from the pulmonary artery to the aorta (bypassing lungs)

Answer 10

ductus arteriosus

Question 11

What is pulmonary blood flow like in the fetus?

Answer 11

minimal

Question 12

A ductus arteriosus that remains open produces a

Answer 12

systolic and diastolic murmur

Question 13

Describe what happens in the lungs with the first breath.

Answer 13

lung expansion–> increased PaO2 and decreased PaCO2–> decreased PVR

Question 14

What leads to an increased SVR for the neonate.

Answer 14

the placenta separates from the uterine wall (or cord clamp)

Question 15

What occurs with a decreased PVR and increased SVR for the neonate?

Answer 15

LA pressure> RA pressure–> the flap valve of the foramen ovale closes

Question 16

What causes closure of the ductus arteriosus?

Answer 16

decreased circulating PGE1 (released from the placenta)
decreased PVR–> reversal of blood flow through the ductus arteriosus–> exposes the DA to increased PO2

Question 17

When does the foramen ovale close?

Answer 17

3 days

Question 18

What leads to closure of the foramen ovale?

Answer 18

LAP>RAP (umbilical cord clamping–> increased SVR)

Question 19

A patent foramen ovale leads to the risk of

Answer 19

paradoxical embolism (the embolus travels to the brain instead of the lungs)

Question 20

When does the ductus arteriosus close?

Answer 20

several weeks via fibrosis

Question 21

A patent ductus arteriosus can be closed with

Answer 21

indomethacin, a prostaglandin synthase inhibitor

Question 22

A patient ductus arteriosus can be opened with

Answer 22

prostaglandin E1 (PGE1)

Question 23

Which conditions increase pulmonary vascular resistance? (select 3)
a. light anesthesia
b. Trendelenburg position
c. alkalosis
d. nitric oxide
e. anemia
f. hypercarbia

Answer 23

a. light anesthesia
b. Trendelenburg position
f. hypercarbia

Question 24

Conditions that increase PVR include

Answer 24

hypercarbia
hypoxemia
acidosis
atelectasis
Trendelenburg position
hypothermia
vasoconstrictors
light anesthesia
pain

Question 25

_____________ occurs when there is abnormal communication between the pulmonary and systemic circulations.

Answer 25

Shunting

Question 26

The size and direction of the shunt are dependent on

Answer 26

three factors

Question 27

The following influence the size and direction of the shunt:

Answer 27

1. ratio of the PVR to SVR 2. pressure gradients between the cardiac chambers or vessels involved 3. compliances of the cardiac chambers

Question 28

Conditions that decrease PVR include

Answer 28

hypocarbia adequate oxygenation alkalosis nitric oxide hemodilution

Question 29

Conditions that increase SVR include

Answer 29

vasoconstrictors, fluid bolus, and increased SNS tone

Question 30

Conditions that decrease SVR include

Answer 30

volatile agents propofol histamine hemodilution sepsis

Question 31

When does a right to left shunt occur?

Answer 31

when PVR is greater than SVR

Question 32

When does a left to right shunt occur?

Answer 32

when SVR is greater than PVR

Question 33

Which congenital defects are MOST likely to cause hypoxemia? (select 3). a. tetralogy of Fallot b. ventricular septal defect c. patent ductus arteriosus d. coarctation of the aorta e. Eisenmenger's syndrome f. Ebstein's anomaly

Answer 33

a. tetralogy of Fallot e. Eisenmenger's syndrome f. Ebstein's anomaly

Question 34

What are the two types of shunts?

Answer 34

cyanotic shunt (R to L) Acyanotic shunt (L to R)

Question 35

Cyanotic shunts include:

Answer 35

Five t's: tetralogy of fallot transposition of the great arteries Tricuspid valve abnormality (Ebstein's anomaly) truncus arteriosus total anomalous pulmonary venous connection

Question 36

Acyanotic shunts include:

Answer 36

ventricular septal defect atrial septal defect patent ductus arteriosus coarctation of the aorta

Question 37

A right to left shunt is associated with a ____________ inhalation induction and a ___________________ IV induction

Answer 37

slower; faster

Question 38

A left to right shunt has ___________________ inhalation induction and _____________________ IV induction

Answer 38

negligible effect on the rate of; possibly prolongs the onset of an

Question 39

______________________ is when a left-to-right shunt changes to a right-to-left shunt secondary to pulmonary hypertension

Answer 39

Eisenmenger syndrome

Question 40

A right to left shunt leads to

Answer 40

decreased pulmonary blood flow hypoxemia LV volume overload LV dysfunction

Question 41

Hemodynamic goals of a right to left shunt include

Answer 41

maintain SVR decrease PVR- hyperoxia, hyperventilation, avoid lung hyperinflation

Question 42

A left to right shunt leads to

Answer 42

decreased systemic blood flow- low cardiac output, hypotension high pulmonary blood flow- pulmonary hypertension, RVH

Question 43

Hemodynamic goals of a left to right shunt include

Answer 43

avoid increased SVR avoid decreased PVR by avoiding alkalosis, hypocapnia, high FiO2, vasodilators

Question 44

Consequences of increased pulmonary blood flow include

Answer 44

ventricular hypertrophy volume overload of both ventricles--> biventricular failure biventricular failure decreased lung compliance + increased airway resistance pulmonary hypertension