Reversed Heart, Situs Inversus and Dextrocardia

Is Your Heart In The Right Place?

heart and lungsThere are some genetic conditions that literally change the layout of your internal organs, including the heart. While rare, many of the people affected by these conditions don’t even know it.

One of these conditions is situs inversus, which causes the internal organs in the upper half of the body (chest and abdomen) to be on the opposite side, in a mirror image of the normal positioning. The liver and stomach, for example, switch position, while the left lung and left atrium of the heart are found on the right hand side.

Why Does It Happen?

Situs inversus occurs due to an autosomal recessive genetic condition, which means that both parents have to be carriers of the altered gene. Statistically, if both parents of a child are carriers, they have a 25% chance of being an unaffected non-carrier, a 50% chance of being a carrier and a 25% chance of inheriting the condition. Because of these chances and the particular genetic circumstances that are required to produce a child with the condition, it’s fairly rare.

This condition is often seen in ‘mirror image twins’. This type of twins is created when one fertilised embryo splits later than is normal for twins. They usually have the exact same physical features but on the opposite sides, so they are mirror opposites. They often write with the opposite hand, for example. In some cases, the twins have opposite internal organ placement too, meaning that one of them has situs inversus.

Types of Situs Inversus

Situs inversus has two subtypes depending on the position of the heart. Dextrocardia is when the left ventricle point is on the right hand side, i.e. the heart is reversed as well as the other organs. Levocardia is when the heart is in the normal position, but the other organs are mirrored.

How Does It Affect Your Life?

Donny Osmand

Donny Osmand

Some people with situs inversus don’t have any related problems because of the condition, and their organs function as normal. However, it can be confusing for doctors. Donny Osmond famously has the condition, but didn’t know until he got appendicitis. As his appendix was on the opposite side to normal, doctors initially misdiagnosed him.

Unfortunately, not everyone with situs inversus is symptom free. Some people have congenital heart defects such as transposition of the great vessels, which is when the aorta and pulmonary artery are switched around. This is apparent very soon after birth though, so there’s no need to worry about this unless you have the situs inversus and are thinking of having children.

A lung condition called primary ciliary dyskinesia (PCD) can also occur, which causes mucus to build up in the lungs and can lead to chronic bronchitis and sinusitis. When someone has both PCD and situs inversus, it’s known as Kartagener syndrome.


Situs inversus can be easily diagnosed by viewing the internal organs via an X-ray, CT scan, MRI scan or ultrasound. As most people don’t have any related problems or symptoms due to this condition, it may be discovered by accident whilst treating something else.

A doctor may also discover the condition by listening to the patient’s heart, as the heartbeat would be unusually loud on their right hand side.