Fetal and Neonatal Circulation

Question 1

How do the following cardiovascular levels change during pregnancy?

• Cardiac Output (CO)
• Systemic Vascular Resistance (SVR):
• Blood Volume & RBC mass
• Blood Pressure

Answer 1

• Cardiac Output (CO) - INCREASED
• Systemic Vascular Resistance (SVR)- DECREASED
• Blood Volume & RBC mass- INCREASED
• Blood Pressure- DECREASED

Question 2

Increased Cardiac Output (CO) results in…..

Answer 2

Results increase blood flow:

• Renal – clearance wastes
• Uterine – nourish fetus

Question 3

Vasodilation of systemic vasculature and renal vessels during pregnancy decreases….

Answer 3

Systemic Vascular Resistance (SVR)

Question 4

Increased blood volume is to needed to:

Answer 4

• Meet the demands of the enlarged pregnant uterus

* Protect against reduced venous return & blood loss during birth

Question 5

Decreases in blood pressure are due to:

Answer 5

• progesterone and estradiol
• increase heat production by fetus
• low resistance circulation - uterus

Question 6

Placenta functions as the …….., ………, ….., and …….. in a fetus.

Answer 6

• Lungs
• Liver
• G.I. Tract
• Kidneys

Question 7

Most oxygenated blood from placenta bypasses through liver by going through the…..

Answer 7

Ductus Venosus

Question 8

Vasoconstriction of the pulmonary vessels results in blood flow shunted through the ….. shunt to redirect blood back to the heart

Answer 8

Ductus Arteriosus

Question 9

Foramen ovale (Shunt) allows blood to flow from right atrium to left atrium. Why does this occur?

Answer 9

• Want to get oxygenated blood from placenta to rest of body- via LEFT ventricle
• Shunt through foramen ovale

Question 10

At birth, the neonate’s lungs expand which causes pulmonary vascular resistance and pulmonary artery pressure to …….

Answer 10

Decrease

Question 11

The increase of pulmonary blood flow at birth causes ………. and increases pressure in the ……

Answer 11

Pulmonary vasodilation

Left Atrium

Question 12

Increased arterial pressure after birth, increases the load of the left ventricle causing it to ……

Answer 12

Hypertrophy

Question 13

The left atrium’s pressure increases high than the pressure of the right atrium causing the …….. to close and eventually fuse.

Answer 13

Foramen Ovale

Question 14

Neonatal Hypoxemia occurs when the pulmonary vascular resistance and pressure remain high and the ……… remains open

Answer 14

Ductus Arteriosus

Question 15

Prolonged Hypoxemia may cause the neonate to be…..

Answer 15

Acidotic

Question 16

Oxygen level and PGE1 are ……. causing the ductus arterious muscle sphincter to vasoconstrict.

Answer 16

Lowered

Question 17

Patent Ductus Arteriosus

Answer 17

Persistent Left to right blood shunting of blood results in:
• excessive blood flow through pulmonary circulation
• hypoperfusion “ductal steal” of the systemic circulation

Question 18

Patients with Patent Ductus Arteriosus, …….. are volume overloaded and leads to ……… failure

Answer 18

Left atrium and ventricular

Left Heart Failure

Question 19

Features of PDA:

Answer 19

Murmur heard during systole and diastole continuous murmur (machinery) murmur

Question 20

Moderate to large shunts of PDA can cause;

Answer 20

• pulmonary edema, hemorrhage, bronchopulmonary dysplasia.

Question 21

Pressure reversal (left becomes greater than right) causes flap over …….. to close

Answer 21

Foramen ovale

Question 22

Most patients with Patent Foramen Ovale are asymptomatic but show increased prevalence for……

Answer 22

Cryptogenic stroke — a stroke in absence of identified cardioembolic or large vessel source and not consistent with small vessel disease

Question 23

Cyanosis, associated with tachypnea and respiratory distress is a clinical finding of ….

Answer 23

Persistent Pulmonary Hypertension

Question 24

Persistent Pulmonary Hypertension is the result of

Answer 24

Continuation of right–to-left shunting of blood through fetal circulatory pathways leading to abnormally high pulmonary vascular resistance (PVR)

Question 25

Other clinical manifestations of Persistent Pulmonary Hypertension

Answer 25

• Cardiac examination: loud, single second heart sound (S2) or a harsh systolic murmur secondary to tricuspid regurgitation.
• May also present systemic hypotension, symptoms of shock, and evidence of poor cardiac function and perfusion.