Cardiovascular System - Fetal Shunts

From Embryology


Fetal circulation

Fetal circulation differs from the adult predominantly due to the presence of 3 vascular shunts located within the heart and in the vasculature.

  • Foramen ovale - in the heart, between the right and left atrium.
  • Ductus arteriosus - in the outflow tract, between the pulmonary artery and descending aorta.
  • Ductus venosus - in the liver circulation, between the umbilical vein and IVC.
Cardiovascular Links: cardiovascular | Heart Tutorial | Lecture - Early Vascular | Lecture - Heart | Movies | 2016 Cardiac Review | heart | coronary circulation | heart valve | heart rate | Circulation | blood | blood vessel | blood vessel histology | heart histology | Lymphatic | ductus venosus | spleen | Stage 22 | cardiovascular abnormalities | OMIM | 2012 ECHO Meeting | Category:Cardiovascular
Historic Embryology - Cardiovascular 
1902 Vena cava inferior | 1905 Brain Blood Vessels | 1909 Cervical Veins | 1909 Dorsal aorta and umbilical veins | 1912 Heart | 1912 Human Heart | 1914 Earliest Blood-Vessels | 1915 Congenital Cardiac Disease | 1915 Dura Venous Sinuses | 1916 Blood cell origin | 1916 Pars Membranacea Septi | 1919 Lower Limb Arteries | 1921 Human Brain Vascular | 1921 Spleen | 1922 Aortic-Arch System | 1922 Pig Forelimb Arteries | 1922 Chicken Pulmonary | 1923 Head Subcutaneous Plexus | 1923 Ductus Venosus | 1925 Venous Development | 1927 Stage 11 Heart | 1928 Heart Blood Flow | 1935 Aorta | 1935 Venous valves | 1938 Pars Membranacea Septi | 1938 Foramen Ovale | 1939 Atrio-Ventricular Valves | 1940 Vena cava inferior | 1940 Early Hematopoiesis | 1941 Blood Formation | 1942 Truncus and Conus Partitioning | Ziegler Heart Models | 1951 Heart Movie | 1954 Week 9 Heart | 1957 Cranial venous system | 1959 Brain Arterial Anastomoses | Historic Embryology Papers | 2012 ECHO Meeting | 2016 Cardiac Review | Historic Disclaimer

Some Recent Findings

Foramen Ovale

Ductus Arteriosus

Ductus Venosus


Atrial Septal Defects

Atrial Septal Defect.jpg Atrial Septal Defects (ASD) are a group of common (1% of cardiac) congenital anomolies defects occuring in a number of different forms and more often in females.
  • patent foramen ovale- allows a continuation of the atrial shunting of blood, in 25% of people a probe patent foramen ovale (allowing a probe to bepassed from one atria to the other) exists.
  • ostium secundum defect
  • endocardial cushion defect involving ostium primum
  • sinus venosus defect - contributes about 10% of all ASDs and occurs mainly in a common and less common form. Common ("usual type") - in upper atrial septum which is contiguous with the superior vena cava. Less common - at junction of the right atrium and inferior vena cava.
  • common atrium

ICD-10 Q21.1 Atrial septal defect Coronary sinus defect Patent or persistent: foramen ovale ostium secundum defect (type II) Sinus venosus defect

Treatment: The surgical repair requires a cardiopulmonary bypass and is recommended in most cases of ostium secundum ASD, even though there is a significant risk involved. Ostium primum defects tend to present earlier and are often associated with endocardial cushion defects and defective mitral or tricuspid valves. In such cases, valve replacement may be necessary and the extended operation has a considerable chance of mortality.

  • Increasingly closure by a transcatheter device closure has been applied.
  • Repair of atrial septal defects on the perfused beating heart (atrial septal defect size 2 cm - 4.5 cm) [2]

Links: Atrial Septal Defects | OMIM: Atrial Septal Defect | Search PubMed | Medline Plus - ASD Repair Video

Patent Ductus Arteriosus

Patent Ductus Arteriosus.jpg Patent ductus arteriosus (PDA), or Patent arterial duct (PAD), occurs commonly in preterm infants, and at approximately 1 in 2000 full term infants and more common in females (to male ratio is 2:1). Can also be associated with specific genetic defects, trisomy 21 and trisomy 18, and the Rubinstein-Taybi and CHARGE syndromes. The opening is asymptomatic when the duct is small and can close spontaneously (by day three in 60% of normal term neonates), the remainder are ligated simply and with little risk, with transcatheter closure of the duct generally indicated in older children. The operation is always recommended even in the absence of cardiac failure and can often be deferred until early childhood.

ICD-10 Q25.0 Patent ductus arteriosus Patent ductus Botallo Persistent ductus arteriosus

Links: Patent Ductus Arteriosus |Search PubMed


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