Problems that cause too much blood to pass through the lungs -- These defects allow oxygen-rich (red) blood that should be traveling to the body to re-circulate through the lungs, causing increased pressure and stress in the lungs. Examples include the following:
Problems that cause too little blood to pass through the lungs - These defects allow blood that has not been to the lungs to pick up oxygen to travel to the body. The body does not receive enough oxygen with these heart problems, and the baby will be cyanotic, or "blue." Examples include the following:
Problems that cause too little blood to travel to the body -- These defects are a result of underdeveloped chambers of the heart or blockages in blood vessels. Examples include:
A combination of several heart defects -- These combinations create a more complex problem that can fall into several of these categories. Complex combination of heart defects include:
The normal heart has two sides, the left and the right, which are separated by a muscular wall called the septum. Each side of the heart also has two parts -- an upper chamber called an atrium, and a lower chamber called a ventricle. Atrial septal defect (ASD), a congenital (present at birth) defect, occurs when there is an opening in the atrial septum, or dividing wall between the two upper chambers of the heart, known as the right and left atria.
Normally, oxygen-poor blood returns to the right atrium from the body, travels to the right ventricle, then is pumped into the lungs where it receives oxygen. Oxygen-rich blood returns to the left atrium from the lungs, passes into the left ventricle, then is pumped out to the body through the aorta.An atrial septal defect allows oxygen-rich blood to pass from the left atrium through the opening in the septum, and then mix with oxygen-poor blood in the right atrium.Treatment can be by 2 methods
Cardiac Catheterization or Device closure: An umbrella shaped device is plced across the defect and enlarged to close it. This does not require any wound on the chest, it is done via blood vessels.
Surgical Repair: Those ASDs that cannot be closed by device are closed by surgery. This can be closed either through the front or from the side.
We have done several hundreds of this surgery during the last few years without any death or serious complications, cosmetic surgeries through thoracotomy are done for female children.
2). VSDVentricular septal defect (VSD), is an opening in the dividing wall between the two lower chambers of the heart known as the right and left ventricles.
A ventricular septal defect allows oxygen-rich blood to pass from the left ventricle through the opening in the septum, and then mix with oxygen-poor blood in the right ventricle.
Cardiac Catheterization: Few VSDs can be closed by devices, a few are being done at our institute
Surgical Repair: Some types of VSDs will close on their own with time. Many, however, are too large or are positioned such that they cannot close on their own and require surgical closure.
Each year more than hundred VSD closures of varying complexity is being done in our unit without any mortality
3). Tetralogy of FallotTetralogy of Fallot is a complex condition with multiple defects 1) VSD 2) Right ventricle outlet is partially obstructed with muscles 3) Right ventricular muscles are thickened 4) Aorta partially arises from the Right ventricle. This i\s the most common blue disorder.
With mild right ventricle obstruction, the pressure in the right ventricle can be slightly higher than the left. Some of the oxygen-poor blood in the right ventricle will pass through the VSD to the left ventricle, mix with the oxygen-rich blood there, and then flow into the aorta. The rest of the oxygen-poor blood will go its normal route to the lungs. These children may have slightly lower oxygen levels than usual, but may not appear blue.
With more serious obstruction in the right ventricle, it is harder for oxygen-poor blood to flow into the pulmonary artery, so more of it passes through the VSD into the left ventricle, mixing with oxygen-rich blood, and then moving out to the body. These children will have lower than normal oxygen levels in the bloodstream, and may appear blue.
Surgical correction is the only hope of cure and is typically carried out through an incision in the middle of the chest. The hole in the wall between the right and left ventricles, or VSD, is closed with a patch of Dacron cloth or a patch of thin leather-like material called pericardium. The muscle bundles and the narrowed pulmonary valve blocking the right ventricle are divided, and the passage out of the right ventricle toward the lungs is widened, usually by applying a patch to this area. Single stage total correction is being done at all ages with excellent results, more than a hundred cases are being done every year.
4). Total anomalous pulmonary venous connection (TAPVC)When a fetus is developing, the pulmonary veins are a single channel which must establish a connection to the developing left atriumthe veins bringing pure blood from the lungs must connect to the left atrium. If it doesn't connect, other pathways for pulmonary venous drainage are created. The surgical repair is to connect the abnormal veins to the left atrium, many a times the child is cooled to very low temperatures and circulation is stopped.
5). Transposition of great arteriesIn transposition of the great arteries, the aorta is connected to the right ventricle, and the pulmonary artery is connected to the left ventricle -- the exact opposite of a normal heart's anatomy.
Oxygen-poor blood returns to the right atrium from the body, passes through the right atrium and ventricle, then goes into the misconnected aorta back to the body.
Oxygen-rich blood returns to the left atrium from the lungs, passes through the left atrium and ventricle, then goes into the pulmonary artery and back to the lungs.
Within the first 1 to 2 weeks of age, transposition of the great arteries is surgically repaired. The procedure that accomplishes this is called a "switch," which roughly describes the surgical process. The aorta and pulmonary arteries are disconnected and reconnected to their proper ventricles. The coronary arteries must be transferred to the newly positioned aorta as well, or "blue" blood will supply the muscle of the heart. Associated holes between the chambers of the heart are closed. The heart is then restarted as the heart-lung machine is withdrawn.
Aterial switch with comlpex anatomy of coronaries are being done, a newborn weighing 1.7kgs was the smallest child treated succesfully.
6). Tricuspid atresiaIn tricuspid atresia, the following occurs:
Improper development of the tricuspid valve prevents oxygen-poor blood from passing from the right atrium to the right ventricle and on to the lungs as it should.
The right ventricle is underdeveloped.
Openings are present in the atrial and ventricular walls , allowing oxygen-poor blood and oxygen-rich blood to mix.
Surgical Repair -- A series of operations are performed in the first two years of life that will re-route blood so that enough oxygen is added to the bloodstream to meet the child's needs. Types of operations include the following:Atrioventricular canal (AV canal or AVC) defect is a complex congenital defect that results in a large hole in the center of the heart. This defect involves several abnormalities of structures inside the heart:
An atrial septal defect allows oxygen-rich blood to pass from the left atrium through the opening in the septum, and then mix with oxygen-poor blood in the right atrium.
A ventricular septal defect allows oxygen-rich blood to pass from the left ventricle through the opening in the septum, and then mix with oxygen-poor blood in the right ventricle.
Abnormalities of the mitral or tricuspid valves allow blood that should be moving forward from the ventricle into either the pulmonary artery or the aorta to instead flow backward into the atria. Surgical repair is the only option, it is a complex repair involving repair of valves and closure of VSD and ASD.