1 Answer

Dextrocardia is a condition in which the heart is pointed toward the right side of the chest instead of normally pointing to the left. It is present at birth (congenital).

Causes
During the early weeks of pregnancy, the baby's heart develops. Sometimes, for reasons that are unclear, the heart develops and turns so that it points to the right side of the chest instead of the left side.

There are several types of dextrocardia. Many types involve other defects of the heart and abdomen area.

The simplest type of dextrocardia is one in which the heart is a mirror image of the normal heart, and no other problems exist. This condition is rare. Often in this case, the organs of the abdomen and the lungs will also be arranged in a mirror image of their normal position. For example, the liver will be on the left side instead of the right.

 http://www.nlm.nih.gov/medlineplus/ency/article/007326.htm 

Dextrocardia is a very rare condition and it has nothing to do with if you're a twin or not.