Introduction
1 in 10,000 people all over the world is diagnosed with heterotaxy syndrome. It is believed that this condition is highly underdiagnosed. Heterotaxy syndrome is a disease where multiple internal organs are misplaced. These organs are mainly the ones present in the abdomen and the chest. The Greek word heterotaxy refers to the atypical arrangement of any specific thing. An individual diagnosed with heterotaxy syndrome will suffer from complicated fetal development defects. Such defects hamper the growth of vital organs such as the liver, spleen, intestines, heart, lungs, and other vital organs.
Our body functions in a standard manner due to the designated locations of particular organs. The heart, spleen, and pancreas are situated on the left side, whereas the majority of the liver is on the right side of the body. Situs solitusrefers to this optimum arrangement of vital organs. In case the orientation is flipped from right to left, the condition is called situs inversus. Heterotaxy syndrome can be understood as a condition where the organs are situated somewhere between situs solitus and situs inversus. This is the reason heterotaxy syndrome is also referred to as situs ambiguous.
What Are the Causes of Heterotaxy Syndrome?
The mutation of multiple genes is the leading cause of heterotaxy syndrome. The genetic proteins produced from the genes help guide the location of the organs while development gets mutated and thus leads to the abnormal formation of the wrong gene code. All of this occurs in the embryonic stage of fetal development. Heterotaxy is extremely rare, but it does run in the family. There are high chances that genetic factors and environmental factors together blend to produce a mutation in the gene.
Below are some of the causes that lead to heterotaxy syndrome;
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Chromosomal insertions.
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Chromosomal deletions.
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Chromosomal rearrangements.
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Pregnant while suffering from diabetes mellitus.
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Smoking while pregnant.
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Ingestion of cocaine during pregnancy.
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Exposure to specific laboratory chemicals during pregnancy.
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Coming in contact with certain hair dyes or toxins during pregnancy.
What Are the Signs and Symptoms of Heterotaxy Syndrome?
Heterotaxy syndrome generally modifies the structure of the heart. In addition to this, it also disrupts the attachments of the blood vessels that carry oxygenated and deoxygenated blood throughout the body. The bronchi of the lungs, spleen being abnormal or even absent, liver capturing the position of the stomach, malrotation, and twisting of the intestine are some of the classical signs and symptoms of heterotaxy syndrome. Mentioned below are a few of the classical signs and symptoms of heterotaxy syndrome.
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Bluish discoloration of the lips.
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A bluish tinge of the skin and nails.
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Difficulty in breathing.
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Congenital heart diseases.
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Fast breathing pattern.
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Abnormally slow heart rate.
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Unusually rapid heart rate.
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Green vomiting.
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Frequent infections in the heart.
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Abnormal position of the heart.
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Dextrocardia.
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Mesocardia.
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Holes in the heart walls.
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Defects in the heart valves.
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Transposition of great arteries or TGA.
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Underdeveloped pumping sections of the heart.
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Reduced cardiac output.
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Abnormal heart rhythm.
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Malfunction of the bile ducts.
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Shortage of oxygen in the body.
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Right-sided cardiac apex.
How to Diagnose Heterotaxy Syndrome?
Heterotaxy syndrome is a congenital condition characterized by internal organs such as the heart not being arranged as expected in the chest. A computed tomography (CT) scan reveals the internal organs in detail. A magnetic resonance imaging (MRI) scan can diagnose a more detailed look at the size, location, and various other malpositioned factors of the heart and other vital organs.
To know the exact cardiac situation, echocardiography or electrocardiography will be necessary. In addition, specific tests that evaluate the normal functioning of organs need to be done. A complete blood picture will also give some insight into the heart’s electrical activity. Ultrasounds and endoscopies are also robust diagnostic tools for heterotaxy. Holter monitor, chest X-rays, and cardiac catheterization are other cardiac imaging tests that can be conducted.
What Is the Treatment for Heterotaxy Syndrome?
The heart is divided into four sections. The upper two heart chambers are the right and left atrium, and the lower sections are the right and left ventricles. Heterotaxy may hamper any or all the chambers of the heart. Since heterotaxy is a syndrome involving multiple organs, treatment is also aligned with correcting all the malpositioned organs. Heart surgery depends on the positions and results of the cardiac diagnostic tools. Any heart defect needs to be immediately managed due to the importance of the organ.
A well-known heart procedure for heterotaxy is the Fontan procedure, where the ventricle of the heart that pumps and transports blood to the whole body is solely corrected. A pacemaker can also be surgically inserted into the heart to manage the abnormal heart rhythm. Prophylactic vaccinations and antibiotic therapy will secure the heart from frequent infections. A heart transplant, being the last option, may also be discussed, but this will require a multidisciplinary approach for patient management.
Conclusion
Heterotaxy is a condition that is congenital in nature but may also develop due to certain environmental factors or as a result of other underlying conditions and syndrome. The vital organs are not positioned in their usual expected location in the chest and abdomen. The heart is one of the major organs that malfunctions the most due to this syndrome. It has been widely studied that most of the complications and complex cases in patients suffering from heterotaxy are due to the cardiac defects found in them. Current advancements in cardiovascular management of heterotaxy patients with better surgical skills and techniques all over the world will hopefully improve the survival rate and outlook of such patients. Early diagnosis is essential, as is in any condition that involves the heart. Heterotaxy remains one of the most challenging congenital defects for cardiologists and pediatric congenital cardiovascular surgeons.
