Usually the heart points towards the left side of the body, as shown above. In dextrocardia, the heart points to the right instead.
The condition is usually not life-threatening, although it often occurs alongside more serious complications, such as heart defects and organ disorders in the abdomen.
Dextrocardia in isolation, without any other heart defects, is unusual.
Contents of this article:
What is dextrocardia?
Dextrocardia is a congenital condition, which is present at birth. There are two major types of dextrocardia.
Dextrocardia situs inversus
In this type of dextrocardia, the tip of the heart and its four chambers are pointing towards the right side of the body
Dextrocardia with situs inversus totalis
With this type of dextrocardia, abdominal and chest organs and other vessels, such as the liver, stomach, and spleen are also out of position. In fact, the other organs are in the opposite position, or in mirror-image reversal, to where they should be.
Causes and risk factors
Dextrocardia is a congenital condition, caused by abnormal genes.
Non-dominant (also called autosomal recessive) genes cause dextrocardia.
These abnormal genes cause the primitive, or cardiac, tube to reverse direction while a fetus is developing in the womb.
Depending on the extent and timing of the reversal, the heart and abdominal organs may also develop in a reversed form.
As it is recessive genes that cause dextrocardia, an individual must inherit a copy of the abnormal gene from both parents to develop the condition.
Dextrocardia affects an estimated 1 out of every 12,000 people. Dextrocardia situs inversus totalis affects approximately 1 out of every 10,000 children. Gender, race, and ethnicity do not seem to have any impact on whether or not a person develops the condition.
Many people with congenital dextrocardia do not always know they have it, as the condition may not produce many symptoms. Often doctors only discover the irregularity while carrying out chest or heart imaging examinations for unrelated complications.
However, one telltale symptom of dextrocardia is that people with this condition have maximum heart sounds on the right of the chest instead of the left.
In severe cases, typically in infants with additional heart defects or another disease, certain symptoms need medical treatment.
Symptoms that require medical attention include:
- unexplained and continual exhaustion
- inability to gain weight
- chronic infections, especially of the sinus and lungs
- difficulty breathing
- jaundiced or yellowed skin
- blue-tinted skin, especially around the fingers and toes
Although the reversed organs themselves may function normally, their irregular positioning often makes the diagnosis of other conditions tricky. For example, in someone with dextrocardia situs inversus, appendicitis will cause sharp pain in the lower left part of the abdomen instead of the right.
When these anatomical differences occur, they can also make surgery difficult.
Other complications associated with dextrocardia may include:
- bowel disorders, usually from obstruction due to malrotation (reversal)
- bronchial diseases, such as like chronic pneumonia, associated primarily with a loss of cilia (hair-like projections) from mucosal tissues
- esophageal disorders
- cardiovascular disorders
- heart failure or disease
- infection and sepsis
Most cases of dextrocardia are diagnosed using an electrocardiogram (EKG) and chest X-ray.
An EKG that shows inverted or reversed electrical waves usually points to dextrocardia.
Once a doctor suspects dextrocardia, they may use a computed tomography (CT) scan or a magnetic resonance imaging (MRI) scan to confirm the condition.
Dextrocardia may be diagnosed using scanning and imagery technology, such as CT scans.
Dextrocardia may be caused by, associated with, or related to other conditions. Complicating conditions include:
Kartagener syndrome is when dextrocardia situs inversus is accompanied by primary ciliary dyskinesia, an inherited condition where the cilia that help move mucus become immobile.
Roughly 20 percent of those with dextrocardia also have Kartagener syndrome.
Dextroversion occurs when the heart is abnormally positioned further to the right and rotated to the right. The right ventricle has usually moved behind the left, but the left ventricle has stayed left. This complication is diagnosed using an electrocardiograph (ECG).
Dextroposition occurs when the heart is displaced or moved to the right. Unlike dextrocardia, the other organs are not mirrored.
This condition is usually associated with acquired diseases of the lungs, diaphragm, or pleura (the membrane surrounding the lungs).
Surgeries and muscle damage or deformities may also contribute to the development of dextroposition.
Doctors will often use an ECG test to distinguish between dextroposition and dextrocardia.[KG3]
Transposition of the great vessels (TGA)
TGA occurs when the major vessels of the heart are connected in reverse due to the reversal of the heart chambers. This condition is pretty rare.
Congenitally corrected transposition of the great arteries (CCTGA)
This condition occurs when the lower half of the heart is reversed, specifically the lower ventricles and the connected valves.
The condition is even rarer than TGA, and the cause is still unknown. According to the Adult Congenital Heart Association, around 0.5 to 1 percent of all babies born with heart problems have CCTGA.
This condition is a congenital defect where the tricuspid valve fails to develop. The tricuspid valve prevents blood from flowing back into the right atrium from the right ventricle.
Single, double-outlet, or double-inlet ventricles
These cases occur when the aorta, which typically transports oxygenated blood from the left ventricle to the rest of the body, and the pulmonary artery, which carries deoxygenated blood from the right ventricle to the lungs, both connect in the same (left or right) ventricle.
Pulmonary stenosis or atresia
This occurs when the pulmonary (pulmonic) valve of the heart that allows blood to leave the heart narrows (stenosis) or fails to develop (atresia).
Heterotaxy happens when mirrored internal organs do not develop or function properly. Depending on the organs involved and the severity of the case, heterotaxy can be life-threatening.
Endocardial cushion defect
This is a congenital heart defect where the tissues that separate the chambers of the heart fail to develop, interfering with blood flow. This condition is also known as atrioventricular canal defect.
Treatment and outlook
Many people with dextrocardia do not display symptoms so the condition can go untreated.
Infants with dextrocardia, which is accompanied by heart defects, may require surgery. Many children will be given medication that increases the force of the heartbeat and lowers their blood pressure before surgery.
For those with Kartagener syndrome, treatment of sinus and lung symptoms may help lessen the chances or impact of dextrocardia.
Treatment options include:
- expectorant or mucous clearing medications
- antibiotics for bacterial infections
- treating cases of bronchitis and sinusitis
Genetic counseling may be helpful for those with dextrocardia who are looking to start a family.
For most people with dextrocardia situs inversus, life expectancy is normal. In cases of isolated dextrocardia, congenital heart defects are more frequent and associated with greater health risks.