During the early weeks of pregnancy, the baby's heart develops. Sometimes, it turns so that it points to the right side of the chest instead of the left side. The reasons for this are unclear.
There are several types of dextrocardia. Many types involve other defects of the heart and abdomen area.
In the simplest type of dextrocardia, the heart is a mirror image of the normal heart and there are no other problems. This condition is rare. When this occurs, the organs of the abdomen and the lungs will often also be arranged in a mirror image. For example, the liver will be on the left side instead of the right.
Some people with mirror-image dextrocardia have a problem with the fine hairs (cilia) that filter the air going into their nose and air passages. This condition is called Kartagener syndrome.
In the more common types of dextrocardia, other heart defects are also present. The most common of these include:
- Double outlet right ventricle (the aorta connects to the right ventricle instead of to the left ventricle)
- Endocardial cushion defect (the walls separating all 4 chambers of the heart are poorly formed or absent)
- Pulmonary stenosis (narrowing of the pulmonary valve) or atresia (pulmonary valve does not form properly)
- Single ventricle (instead of two ventricles, there is a single ventricle)
- Transposition of the great vessels (the aorta and pulmonary artery are switched)
- Ventricular septal defect (hole in the wall that separates the right and left ventricles of the heart)
The abdominal and chest organs in babies with dextrocardia may be abnormal and may not work correctly. A very serious syndrome that appears with dextrocardia is called heterotaxy. In this condition, many of the organs are not in their usual places and may not work properly. For example, the spleen may be completely missing. The spleen is an important part of the immune system, so babies born without this organ are in danger of severe bacterial infections and death. In another form of heterotaxy, several small spleens exist, but they may not work correctly.
Heterotaxy may also include:
- Abnormal gallbladder system
- Problems with the lungs
- Problems with the structure or position of the intestines
- Severe heart defects
- Abnormalities of the blood vessels
Possible risk factors for dextrocardia include a family history of the condition.