Exam 2: Ch 19 Fetal Circulation & Congenital Cardiac Defects

Question 1

physiology of fetal circulation

Answer 1

low PO2 (30-35 mmHg)

high CO

Hgb has high O2 affinity

Question 2

umbilical arteries and veins in fetal circulation

Answer 2

arteries: take off from femorals, carry low O2 blood to placenta
veins: flow into liver, carry high O2 blood from placenta to fetus

Question 3

ductus venosus (fetal circ)

Answer 3

bypasses hepatic tissue

joins IVC (brings high O2 blood)

mixing reduces O2 saturation

Question 4

ductus arteriosus

Answer 4

opening from pulmonary artery to aorta

allows blood to bypass lungs: closes at birth

Question 5

foramen ovale

Answer 5

opening from right to left artium

allows blood to bypass lungs: closes at birth

Question 6

shunting

Answer 6

movement of blood between pulmonary and systemic circulations

direction determined by pressure (resistance)

Question 7

L –> R shunt defect

Answer 7

from LA to RA, LV to RV, aorta to PA

ASD, VSD, PDA

produce little cyanosis

Question 8

R –> L shunt defect

Answer 8

flow from RV to LV through VSD when pulmonary valve resistance is high (doesn’t go through lungs)

tetrology of Fallot

transposition of great vessels

cyanosis

high PA blood flow –> PA HTN

Question 9

diagnosis/treatment of shunting defects

Answer 9

Dx: ultrasound, fetal echoes after 16wks

Rx: supportive medical care, surgery

Question 10

PDA

Answer 10

blood flows from aorta to PA (doesn’t close L –> R shunt)

Rt HF, pulmonary edema

treatment: indomethacin inhibits prostaglandin syn., or surgery

Question 11

ASD/VSD

Answer 11

blood flows from LV to RV or LA to RA (L –> R shunt)

Rt HF and pulmonary edema

pulmonary HTN in VSD

treatment: spontaneous of catheter closure

Question 12

tetralogy of Fallot

Answer 12

VSD, pulmonary stenosis, overriding aorta (over VSD), RV hypertrophy and HTN

blood flows from RV to LV (R –> L shunt) –> aorta receives blood from both RV and LV

blue baby

surgery

Question 13

transposition of great vessels

Answer 13

aorta from RV and PA from LV

must have some communication between circuits for life (PDA or septal defect)

prostaglandins keep PDA open, surgery

Question 14

coarctation of aorta

Answer 14

narrow aorta

BP in arms > legs

balloon angioplasty or open surgery

Question 15

only functional single ventricle

Answer 15

single Rt or Lt

single Rt with hypoplastic left

RV supplies lungs and systemic circulation via PDA

palliative surgery, but no full correction possible

Question 16

Kawasaki disease

Answer 16

acute vasculitis which may involve coronary arteries

immune system origin

acquired heart disease of young children

Question 17

symptoms of Kawasaki disease

Answer 17

conjunctivitis

hand and foot swelling

swollen cervical lymph nodes

CA aneurysms

Question 18

treatment of Kawasaki disease

Answer 18

gamma globulin

aspirin