Heart defects remain some of the most common of birth defects. Not all are expressed directly at birth and some are so mild they don’t need treatment right away, or may heal on their own and never require treatment. Others are severe and will need emergency intervention, but with this intervention many children are able to live normal and healthy lives and have an excellent life expectancy.
Types of heart defects are often grouped by what part of the heart they affect. These would include defects of the heart valves, the septum, the interior valves of the heart, or the ventricles. Other types of heart defects combine several defects at once or have to do with the way the heart looped when it formed.
Valve defects can refer especially to defects of the aortic and pulmonary valves, which are the great arteries that come off of the two bottom chambers of the heart, called the ventricles. Sometimes the valves are transposed (transposition of the great arteries or TGA) and this immediately necessitates repair after a baby is born. Children with this condition are frequently cyanotic (blue), and will die shortly after being born if they do not get surgical repair. Other times one or both arteries are narrowed (stenotic) which can prevent blood flowing properly from the heart. This can cause extra pressure in the heart and heart failure. Narrowing may be slight, or very severe, and occasionally a valve is almost completely absent or closed (atresia).
Defects of the septum refer to problems with the wall that separates right hand and left hand chambers. Often the septum has failed to fully close which can result in small holes and communication between right and left side. When these holes are present in the bottom two chambers they are called ventricular septal defects (VSDs), and when they’re present in the top two chambers they’re called atrial septal defects (ASD). Holes may be so small that very little blood leaks back and forth between the atria or ventricles, but they can be large or multiple in number too, and require repair to close the communication/s.
Sometimes the valves in the heart that separate bottom and top chambers fail to form properly. Conditions like tricuspid atresia may need immediate medical attention. Some people have minor defects in their mitral valve (left side) that aren’t noticed until they are in their teens or older. Surgical repair may be necessary to treat the mitral valve at a later point.
Heart defects in the ventricles may also occur, and these may be some of the more challenging conditions to treat. These important pumping chambers can be too small or hypoplastic, necessitating several surgeries to palliate the condition. It’s also possible to have a mixed group of defects that may require significant intervention. It’s not at all impossible for a child to be born with a ventricular septal defect, a hypoplastic ventricle, and a stenotic valve or transposition of the valves.
Some defects are very unusual and cause the heart to loop the wrong way when it is forming. In dextrocardia, the heart is on the right side of the chest, and in mirror image forms, all of the organs are a mirror image of the average human body. In certain conditions dextrocardia presents with absence of a spleen or multiple spleens, and the heart may have several congenital anomalies in addition to having looped the wrong way.
It’s valuable to realize that despite the gravity of defects that can exist in the heart, there are wonderful specialists who can treat these conditions, and surgery plus outlook continues to improve for those many congenital heart defects. A number of conditions that were once thought irreparable are now being repaired on a regular basis, and the most aggressive potential repair of a very damaged heart, transplant, continues to improve in survival rate, too.