2. ASD and PFO are different types of
interatrial defect
Septum primum forms first .it leaves window ,Ostium secundum
septum secundum forms later .usually covers Ostium secundum
3. Foramen ovale intrauterine allow blood to flow
From right to left by passing the lung
It closes after birth
But stays open in 25-28 % of people
4. If the septum secundum fails to cover the ostium secundum .blood
flow in both direction causing atrial septal defect OSD
Inferior limb
septum primum.
superior limb
septum primum.
superior limb
septum secundum.
inferior limb
septum secundum.
5. Patent Foramen Ovale
An interatrial communication between the superior limb of the septum secundum on the right side
the septum primum on the left atrial side .• The flap of the foramen ovale (FO) can often be seen
6. Foramen ovale is
defect in septum
secundum
Ostium Secundum
Atrial Septal Defect
Defect in the septum
primum.
9. ostium primum
ostium primum atrial septal defect is a defect in the atrial
septum at the level of the tricuspid and mitral valves
10.
11.
12. ASD and PFO can diagnosed by TEE but not excluded by it
No shunt seen by echo not mean that no PFO or small ASD
Defect Anterior to FO = primum defect (often w MV cleft)
Defect Post/Sup to FO = sinus venosus defects (often w anomalous R
pulm vn connection)
Ostium Primum Atrial Septal Defect :Located in the most anterior
and inferior aspects of the atrial septum. near the atrioventricular
valves
sinus venosus type ASD, situated near the entry of the SVC or IVC
13. Indication to close ASD
RV /RA enlarged
QP : QS more than 1.5
Paradoxical embolism
14. PATENT FORAMEN OVALE ASD OSTIUM
Right to left shunt Left to right shunt
normal or slightly elevated
pulmonary pressure,
pulmonary hypertension of different
degree,
normal Qp/Qs ratio , an increased Qp/Qs ratio
normal right chambers enlarged right chambers
ostium secundum ASD, placed in
the midportion of the septum in the
area of the fossa ovalis