Healthy Heart Function
Normal blood flow through the heart begins with deoxygenated blood (depicted as blue) passing through the vena cava, from the body tissues, and into the right atrium of the heart. From there, atrial contraction pushes the blood through the tricuspid valve into the right ventricle (figure B). Blood then moves with low pressure through the pulmonary valve and to the pulmonary artery (figure C) which transports blood to the lungs where it becomes oxygenated. Oxygenated blood (depicted as red) now flows to the left atrium (figure D), and then, with atrial contraction, continues through the mitral valve to the left ventricle. Ventricular contraction pushes the blood through the aortic valve, into the aorta, and out to the body (figure E).
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Atrial and Ventricular Septal Defects
What are they?
These defects are holes that form in the septum between either the right and left atrium (Atrial Septal Defect), the right and left ventricle (Ventricular Septal Defect), allowing the mixing of oxygenated and deoxygenated blood to pass between the chambers. These holes may be small, medium, or large, and vary in the amount of blood that they allow to pass through.
What Causes it?
As the heart forms in the developing fetus, it has many holes in it which eventually close up during pregnancy or shortly after birth. For reasons not completely understood, occasionally these holes between the heart chambers do not close, causing septal defects. Atrioventricular Canal Defects have been known to form more commonly in children with chromosomal disorders such as down syndrome.
How Does it Affect the Body?
In septal defects, oxygenated blood is shunted from the left side of the heart to the right, which puts increased strain on the right side of the heart and lungs as they work to circulate the extra blood volume. Over time, and if the hole is large, strain begins to show on pulmonary arteries, blood becomes backed up, leading to congested lungs, and over time can be backed up to other parts of the body, and finally, lower cardiac output results from oxygenated blood being shunted through the heart rather than out to the rest of the body.
These defects are holes that form in the septum between either the right and left atrium (Atrial Septal Defect), the right and left ventricle (Ventricular Septal Defect), allowing the mixing of oxygenated and deoxygenated blood to pass between the chambers. These holes may be small, medium, or large, and vary in the amount of blood that they allow to pass through.
What Causes it?
As the heart forms in the developing fetus, it has many holes in it which eventually close up during pregnancy or shortly after birth. For reasons not completely understood, occasionally these holes between the heart chambers do not close, causing septal defects. Atrioventricular Canal Defects have been known to form more commonly in children with chromosomal disorders such as down syndrome.
How Does it Affect the Body?
In septal defects, oxygenated blood is shunted from the left side of the heart to the right, which puts increased strain on the right side of the heart and lungs as they work to circulate the extra blood volume. Over time, and if the hole is large, strain begins to show on pulmonary arteries, blood becomes backed up, leading to congested lungs, and over time can be backed up to other parts of the body, and finally, lower cardiac output results from oxygenated blood being shunted through the heart rather than out to the rest of the body.
How can I assess for it?
Atrial septal defects in particular have more subtle manifestations and are often not diagnosed in infancy. The hallmark of this defect is a splitting of the second heart sound, with a grade 2 or 3 murmur present heard over the left sternal border. Ventricular septal defects can cause few to no symptoms if the hole in the septum is small in size. In many cases, the only thing that might be detected is a heart murmur. Medium to large defects may present any of the following symptoms at any time after birth:
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Retrieved from https://www.youtube.com/watch?v=7oKz6J0Ay_I
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How is it Treated?
If the hole in the septum is small, it will not put much strain on the heart and lungs, and will often close up on its own without any intervention. Larger, symptomatic septal defects often require repair of the septal wall which can be done through open heart surgery or cardiac catheterization. There are no medications that can repair septal defects, or speed along self repair, but medications such as Digoxin and Lasix can be used to manage symptoms until repair can be made.
If the hole in the septum is small, it will not put much strain on the heart and lungs, and will often close up on its own without any intervention. Larger, symptomatic septal defects often require repair of the septal wall which can be done through open heart surgery or cardiac catheterization. There are no medications that can repair septal defects, or speed along self repair, but medications such as Digoxin and Lasix can be used to manage symptoms until repair can be made.