Cyanosis Due to Patent Foramen Ovale PFO

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Cyanosis Due to Patent Foramen Ovale (PFO)
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A newborn baby has an average blood volume equal
to approximately 7 of his body weight

• For example If a baby weighs 3.5 kg, and 1L of
  blood weighs approximately 1 kg, the estimated
  total blood volume of the baby is .245 liters.
• (3.5 kg) (.07) ? (.245 kg) (1L / 1kg) ? .245 L
  blood volume.

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Once apon a time...

• At birth, Jimmys hematocrit was normal, but
  after about 3 weeks at home, the mother noted
  that Jimmy exhibited periods of cyanosis around
  the his mouth during vigorous crying
• Imaging studies revealed a small patent foramen
  ovale. The physician explained to the mother that
  there is no reason to surgically correct the
  defect, because the heart and blood will
  compensate for it over time .

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Cyanosis

• Cyanosis is a physical sign causing bluish
  discoloration of the skin and mucous membranes.
  Cyanosis is caused by a lack of oxygen in the
  blood.
• Blood contains a red pigment (hemoglobin) in its
  red blood cells. Hemoglobin picks up oxygen from
  the lungs, then circulates it through arteries
  and releases it to cells through tiny
  capillaries. After giving up its oxygen, blood
  circulates back to the lungs through capillaries
  and veins. Hemoglobin, as well as blood, is
  bright red when it contains oxygen, but appears
  dark or "bluish" after it gives up oxygen.
• The blue color of the skin and mucous membranes
  is caused by a lack of oxygen in the blood. Low
  blood oxygen may be caused by poor blood
  circulation, or heart or breathing problems

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In Jimmys Case

• Cyanosis can be present at birth as a sign of
  congenital heart disease, in which some of the
  blood is not pumped to the lungs where oxygen
  would make the blood a bright red color. Instead,
  the blood goes to the rest of the body and
  remains unoxygenated
• Fetuses have a normal opening between the left
  and right atria (upper chambers) of the heart. If
  this opening fails to close naturally soon after
  the baby is born, the condition is called patent
  foramen ovale (PFO).
• PFO is the persistence of a fetal opening between
  the left and right atria (upper chambers) of the
  heart. This hole allows blood to bypass the
  lungs, because they are not used until a baby is
  born. The foramen ovale normally closes soon
  after the infant is born, but didnt in Jimmys
  case.

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PFO
This slide simply shows the PFO that exists
between the left and right atria within the heart
that failed to close after Jimmys birth.
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Why is this ok?
Jimmys mom should not be worried because under
normal condition where PFO is present, with in
the first year of the babys life the valve will
usually close do to the pressure inside the
heart. This is the case with 80 of the babies
that are born with PFO. Also, another hypothesis
that we came up with (so it doesnt mean its
right) The babies body may compensate for the
low oxygen carrying capacity of the blood by
producing either more red blood cells or by
producing more hemoglobin which carries the
oxygen molecules.
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Analogy

• Think about a race car course