Fetal and Neonatal Circulation Flashcards
How do the following cardiovascular levels change during pregnancy?
- Cardiac Output (CO)
- Systemic Vascular Resistance (SVR):
- Blood Volume & RBC mass
- Blood Pressure
- Cardiac Output (CO) - INCREASED
- Systemic Vascular Resistance (SVR)- DECREASED
- Blood Volume & RBC mass- INCREASED
- Blood Pressure- DECREASED
Increased Cardiac Output (CO) results in…..
Results increase blood flow:
- Renal – clearance wastes
- Uterine – nourish fetus
Vasodilation of systemic vasculature and renal vessels during pregnancy decreases….
Systemic Vascular Resistance (SVR)
Increased blood volume is to needed to:
- Meet the demands of the enlarged pregnant uterus
* Protect against reduced venous return & blood loss during birth
Decreases in blood pressure are due to:
- progesterone and estradiol
- increase heat production by fetus
- low resistance circulation - uterus
Placenta functions as the …….., ………, ….., and …….. in a fetus.
- Lungs
- Liver
- G.I. Tract
- Kidneys
Most oxygenated blood from placenta bypasses through liver by going through the…..
Ductus Venosus
Vasoconstriction of the pulmonary vessels results in blood flow shunted through the ….. shunt to redirect blood back to the heart
Ductus Arteriosus
Foramen ovale (Shunt) allows blood to flow from right atrium to left atrium. Why does this occur?
- Want to get oxygenated blood from placenta to rest of body- via LEFT ventricle
- Shunt through foramen ovale
At birth, the neonate’s lungs expand which causes pulmonary vascular resistance and pulmonary artery pressure to …….
Decrease
The increase of pulmonary blood flow at birth causes ………. and increases pressure in the ……
Pulmonary vasodilation
Left Atrium
Increased arterial pressure after birth, increases the load of the left ventricle causing it to ……
Hypertrophy
The left atrium’s pressure increases high than the pressure of the right atrium causing the …….. to close and eventually fuse.
Foramen Ovale
Neonatal Hypoxemia occurs when the pulmonary vascular resistance and pressure remain high and the ……… remains open
Ductus Arteriosus
Prolonged Hypoxemia may cause the neonate to be…..
Acidotic
Oxygen level and PGE1 are ……. causing the ductus arterious muscle sphincter to vasoconstrict.
Lowered
Patent Ductus Arteriosus
Persistent Left to right blood shunting of blood results in:
• excessive blood flow through pulmonary circulation
• hypoperfusion “ductal steal” of the systemic circulation
Patients with Patent Ductus Arteriosus, …….. are volume overloaded and leads to ……… failure
Left atrium and ventricular
Left Heart Failure
Features of PDA:
Murmur heard during systole and diastole continuous murmur (machinery) murmur
Moderate to large shunts of PDA can cause;
- pulmonary edema, hemorrhage, bronchopulmonary dysplasia.
Pressure reversal (left becomes greater than right) causes flap over …….. to close
Foramen ovale
Most patients with Patent Foramen Ovale are asymptomatic but show increased prevalence for……
Cryptogenic stroke — a stroke in absence of identified cardioembolic or large vessel source and not consistent with small vessel disease
Cyanosis, associated with tachypnea and respiratory distress is a clinical finding of ….
Persistent Pulmonary Hypertension
Persistent Pulmonary Hypertension is the result of
Continuation of right–to-left shunting of blood through fetal circulatory pathways leading to abnormally high pulmonary vascular resistance (PVR)
Other clinical manifestations of Persistent Pulmonary Hypertension
- 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.
