PATENT DUCTUS ARTERIOSUS (PDA)

The ductus arteriosus is a normal fetal structure, allowing blood to bypass circulation to the lungs. Since the fetus does not use his/her lungs (oxygen is provided through the mother’s placenta), flow from the right ventricle needs an outlet. The ductus provides this, shunting flow from the left pulmonary artery to the aorta just beyond the origin of the artery to the left subclavian artery. The high levels of oxygen which it is exposed to after birth causes it to close in most cases within 24 hours. When it doesn’t close, it is termed a Patent Ductus Arteriosus.

The defect often corrects itself within several months of birth, but may require infusion of chemicals, the placement of "plugs" via catheters, or surgical closure.

 

The flow pattern is similar to the septal defects noted above, except that the shunting occurs outside of the heart. The left ventricle has to pump blood out through the aorta, only to have some of it flow to the lower pressure pulmonary artery, and directly back to the left atrium and ventricle. If a large PDA is not corrected, then the pressures in the pulmonary arteries may become very high and induce changes in the arteries themselves such that even closure of the defect will no longer improve the patient. In this case, the pressures in the right side of the heart are high enough that blood may begin to flow from the right to the left side of the heart. This situation is called "Eisenmenger’s syndrome", a condition which may result from several similar abnormalites.
©COPY;1997 HeartPoint    Updated November 1997

For more about Congenital Disease, also see these related subjects on HeartPoint:

| Congenital Heart Disease |  Atrial Septal Defect  |  Coarctation of the Aorta  |   Ebstein's Anomaly  |  Patent Ductus   |  Tetralogy of Fallot  |
|  Transposition of the Great Vessels |  Truncus Arteriosus  |  Ventricular Septal Defect  |

|  Commentary  |  Food You Will Love  |  HeartPoint Gallery  |  In The News |  Health Tips  |  What's New
|  Information Center  |  Home  |

This site presents material for your information, education and entertainment. We can assume no liability for inaccuracies, errors, or omissions. Above all, material on this site should not take the place of the care you receive from a personal physician. It is simply designed to help in the understanding of the heart and heart disease, and not as a diagnostic or therapeutic aid. You should seek prompt medical care for any specific health issues. Please feel free to browse the site and download material for personal and non-commercial use. You may not however distribute, modify, transmit or reuse any of these materials for public or commercial use. You should assume that all contents of the site are copyrighted. ©COPY;1997 HeartPoint