Dextro-transposition of the great arteries pathophysiology
|
Dextro-transposition of the great arteries Microchapters |
|
Differentiating dextro-transposition of the great arteries from other Diseases |
|---|
|
Diagnosis |
|
Treatment |
|
Case Studies |
|
Dextro-transposition of the great arteries pathophysiology On the Web |
|
American Roentgen Ray Society Images of Dextro-transposition of the great arteries pathophysiology |
|
FDA on Dextro-transposition of the great arteries pathophysiology |
|
CDC on Dextro-transposition of the great arteries pathophysiology |
|
Dextro-transposition of the great arteries pathophysiology in the news |
|
Blogs on Dextro-transposition of the great arteries pathophysiology |
|
Risk calculators and risk factors for Dextro-transposition of the great arteries pathophysiology |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Priyamvada Singh, M.B.B.S. [2]; Cafer Zorkun, M.D., Ph.D. [3]; Keri Shafer, M.D. [4]; Assistant Editor(s)-In-Chief: Kristin Feeney, B.S. [5]
Anatomy and Anatomic Variations
- In dextro-transposition of the great arteries there exist an arterial-ventricular discordance with atrial-ventricular concordance.
- The position of the aorta and the pulmonary artery is switched relative to the ventricular septum.
- The atrio-ventricular connections are normal.
- Differences in the shape of the atrial septum and/or ventricular outflow tracts affect the anatomical positions of the aorta and pulmonary artery.
- In the majority of d-TGA cases, the aorta is anterior and to the right of the pulmonary artery, but it can also be directly anterior or anterior and to the left.
- The aorta and pulmonary artery can also be side by side, with the aorta located on either side. This is a less common variant, and with this arrangement, an unusual coronary artery pattern is common.
- There are also some cases in which the aorta to the right and posterior to the pulmonary artery.[1]
- The left coronary artery arises from the left aortic sinus and the right coronary artery from the posterior aortic sinus. In 31 of 149 cases, the circumflex originates from the posterior aortic sinus. [2]
Pathophysiology
- In a normal heart, oxygen-depleted (blue) blood is pumped from the right heart, through the pulmonary artery, to the lungs where it is oxygenated. The oxygen-rich red blood then returns to the left heart, via the pulmonary veins, and is pumped through the aorta to the rest of the body, including the heart muscle itself.
- With d-TGA, blue blood from the right heart is pumped immediately through the aorta and circulated to the body and the heart itself, bypassing the lungs altogether, while the left heart pumps red blood continuously back into the lungs through the pulmonary artery.
- In effect, two separate "circular" (parallel) circulatory systems are created, rather than the "figure 8" (in series) circulation of a normal cardio-pulmonary system.
- In d-TGA, the pulmonary and the systemic circuits are in parallel circulation, rather than in series, which is incompatible with life if there is no mixing of the two systems. Therefore, in most cases, a complex d-TGA is the one that allows survival due to the presence of other heart defects like patent foramen ovale (PFO) for mixing blood between the two systems. Other possible mixing sites include a PDA or a VSD.
- The course of TGA is determined by the degree of hypoxia, and the ability of each ventricle to sustain an increased work load in the presence of reduced coronary arterial oxygenation. It is also important the nature of associate heart defects, and the status of the pulmonary vascular circulation.
- The pulmonic flow is increased in those cases with transposition and large VSD or large PDA without obstruction to left ventricular outflow. In these cases, pulmonary vascular obstruction develops by 1 to 2 years of age.
References
Acknowledgements and Initial Contributors to Page
Leida Perez, M.D. nl:Transpositie van de grote vaten Template:WH Template:WS