The chance of having the heart on the right side is about 1 in 100,000, and it is caused by a mutation in the gene locus during the development of the human embryo. A right-sided heart is also called a mirror-right heart, resulting in the main body of the heart being on the right side of the chest and the other organs being in the opposite position to normal. The right side of the heart is a congenital variant, not a congenital malformation or an organic lesion. There are also individual patients whose heart is on the right side as a pathological condition, also known as a right-shifted heart, which is commonly associated with congenital malformations of the great vessels. Patients with a heart on the right side can work and live normally with no particular effects.