Birth Defects Heart Tgv

Congenital heart defects are malformations of the heart that occur during fetal development that can affect many of the heart’s structures. Transposition of the great arteries (TGA), also known as transposition of the great vessels (TGV), is a congenital defect affecting the two main arteries leaving the heart: the aorta and the pulmonary artery.

Heart Anatomy and TGV

In a healthy heart, deoxygenated blood from the body is pumped into the right atrium, travels to the right ventricle, and is pumped to the lungs via the pulmonary artery. There the blood is oxygenated, then pumped back into the left atrium. It then travels to the left ventricle, and is pumped out to the body via the aorta.

In a heart with TGV, however, the connections are reversed: The pulmonary artery is connected to the left ventricle, and the aorta is connected to the right ventricle. This means that deoxygenated blood from the body is taken into the right atrium, transmitted to the right ventricle, and pumped back into the body via the aorta. Oxygenated blood comes from the lungs to the left atrium, is transmitted to the left ventricle, and is then pumped back to the lungs via the pulmonary artery. Transposition of the great arteries prevents deoxygenated blood from reaching the lungs, and prevents oxygenated blood from reaching the body.

In many cases, TGA co-occurs with other congenital heart defects (such as a ventricular septal defect, or hole in the wall separating the right and left ventricles). This other defect can allow for mixing of the oxygenated and deoxygenated blood, allowing for at least some oxygenated blood to get out to the body. However, even in this case, blood oxygenation levels are insufficient to support the body, and increased strain can damage the heart. Resulting symptoms can include increased breathing and heart rate.

Treatment for Transposition of the Great Vessels

Initial TGV treatment may involve giving the infant oxygen and medications to improve mixing of oxygenated and deoxygenated blood. Intermediate TGV treatment sometimes involves cardiac catheterization and balloon atrial septoplasty.

During atrial septoplasty, a small tube is inserted through a vein in the leg, and threaded up to the heart. A small balloon is threaded with the catheter, and expanded in the foramen ovale, which is a natural connection between the left and right atria present in infants before birth. This facilitates blood mixing until further surgery is performed.

Finally, usually within the first week of life, an arterial switch operation is performed to connect the aorta and pulmonary artery in their proper places. Children who have this surgery can usually lead normal lives, but as with other congenital heart defects, they must be continually monitored by a cardiologist.

Resources

Children’s Hospital Boston. (n.d.). Transposition of the great arteries.Retrieved April 12, 2010, from: http://www.childrenshospital.org/az/Site511/mainpageS511P0.html.

Cincinnati Children’s Hospital. (n.d.). Transposition of the great arteries.Retrieved April 11, 2010, from: http://www.cincinnatichildrens.org/health/heart-encyclopedia/anomalies/transposition.htm.

Medline Plus. (n.d.). Transposition of the great vessels. Retrieved April 11, 2010, from: http://www.nlm.nih.gov/medlineplus/ency/article/001568.htm.