What is Cor Triatriatum?
Cor triatriatum is an unusual condition where a baby is born with a thin, muscle-like membrane that splits the right or left atrium of the heart into three parts, instead of two. This is considered a type of heart defect present at birth, or a congenital heart defect. The most common type of this condition is called cor triatriatum sinister, in which the left atrium of the heart is split into an upper and a lower section. The upper part receives blood from the lung veins, while the lower part connects to an additional piece of heart tissue. This connection can block the opening to the heart’s main pumping chamber, called the left ventricle, creating a significant obstacle to the flow of blood.
What makes cor triatriatum different from another type of congenital heart defect, called supravalvular mitral stenosis, is the presence of this additional piece of heart tissue.
Another, even rarer, form of this condition exists called cor triatriatum dextrum. In this case, an extra valve in the heart persists, dividing the right atrium of the heart into two sections. This condition can appear similar to something called the Ebstein anomaly, and it can be hard to tell the two apart.
What Causes Cor Triatriatum?
Cor triatriatum is a condition that happens when the common pulmonary vein, which should normally be absorbed in the development stages of a fetus, isn’t fully absorbed. This incomplete process leads to the creation of an extra part that divides the left heart chamber into two. It’s important to note that there are no identified genetic changes or risk factors linked with this condition.
Risk Factors and Frequency for Cor Triatriatum
Cor triatriatum, a rare heart defect, is often found alongside other heart problems that a person is born with. These can include tetralogy of Fallot, atrial septal defect, ventricular septal defect, and partial anomalous pulmonary venous connection. Despite these associations, cor triatriatum is very rare and only makes up 0.1% to 0.4% of all congenital heart abnormalities. The condition is defined by a membrane in the heart that may be complete or have one or more holes of varying sizes.
Signs and Symptoms of Cor Triatriatum
Cor triatriatum is a rare heart condition that shows up during infancy, producing signs of high blood pressure in the lungs and blocked blood flow in the lungs. This condition can cause issues like poor growth and weight increase, feeding problems, breathing difficulties, and spells of pale or blue skin in kids. In adults, the disease is typically associated with high blood pressure in the lungs and heart failure due to the membrane becoming hardened and the opening in the heart becoming smaller. It can lead to heart valve leakage and irregular heartbeats, posing serious risks.
The common features of cor triatriatum include:
- Breathing difficulties and shortness of breath when lying flat
- Feeling tired easily
- Coughing up blood
- Trouble exercising and experiencing shortness of breath
- Feeling heart palpitations
Irregular heartbeat can cause blood clots, producing symptoms of a lung clot or a stroke. The left chamber of the heart can swell as blood backs up, leading to harmful irregular heartbeats.
Notably, adult presentation of cor triatriatum is rare and shares many symptoms with a condition known as mitral stenosis. However, the absence of a loud heart sound and an opening snap can help differentiate the two. A chest x-ray showing lung congestion without heart enlargement is typical of cor triatriatum, and a Doppler echocardiogram can confirm the diagnosis.
The physical examination of a patient with cor triatriatum would reveal signs of heart failure and fluid in the lungs. These signs could include:
- An intensified sound of blood flow in the lungs
- A mild mid-heartbeat murmur at the upper left side of the chest
- A right ventricular thrust or swelling
- Rales, or crackles, heard in the lungs
- Weak peripheral pulses
- Enlarged liver and tenderness in the right upper abdomen
- Ascites, or fluid in the abdomen
- Swelling in the legs and arms
- Enlarged veins in the arms and legs
- Enlarged and prominent neck veins with high vein pressure
- Pale skin color
- Poor weight gain
Testing for Cor Triatriatum
The key methods for evaluating and diagnosing certain heart conditions involve detailed imaging studies. These can include chest x-rays, electrocardiograms (EKGs), echocardiograms, angiograms, and exploratory heart procedures called catheterizations.
A chest x-ray is often the first test done. It can show various signs of heart issues, like lung congestion, fluid build-up around the lungs, an enlarged heart, and more.
An EKG, on the other hand, doesn’t provide specific results for a condition called cor triatriatum. It could show anything from an irregular heart rhythm called atrial fibrillation to abnormal heart muscle thickening.
Echocardiography, which uses sound waves to create a detailed image of the heart, is the preferred diagnostic tool. It provides a clear picture of the heart’s structure and function, including identifying defects, visualizing blood flow patterns, and more. So clear that it can differentiate between cor triatriatum and a similar condition called supravalvular mitral stenosis.
In older patients, a form of echocardiography called transesophageal echocardiography provides a precise understanding of any defects. If this isn’t possible, echocardiography using a device on the chest can be done instead.
Lastly, angiography helps determine the seriousness of any blockages and pinpoints the ideal time for surgery.
Treatment Options for Cor Triatriatum
If a patient has no signs or symptoms, they usually don’t require any special treatment. The doctor will, however, keep an eye on their condition and schedule regular check-ups.
For patients showing symptoms, there are two main approaches to treatment: conservative medical management and surgical intervention. The first step in medical treatment involves stabilising the patient if they have fluid overload and breathing difficulties. For patients suffering from an irregular heartbeat known as atrial fibrillation, treatment can involve controlling heart rate and rhythm, administering anticoagulants (anti-clotting drugs), and taking steps to prevent other serious conditions such as deep vein thrombosis, pulmonary embolism, and stroke. A surgical consultation is often recommended for these patients as well.
Surgery is considered the best treatment. This involves removing the extra pouch or membrane in the heart through an incision down the middle of the chest, using a heart-lung bypass machine during the procedure. After the pouch is taken out, the hole in the upper chambers of the heart (the atria) is closed using a piece of the sac covering the heart (the pericardium). This surgery has an overall 10-year survival rate of 83%. However, patients who also have other congenital heart conditions may face a higher risk of complications and have a lower survival rate.
What else can Cor Triatriatum be?
When a doctor suspects a heart condition called cor triatriatum, there are a number of other similar heart problems they also need to consider. These could include:
- Two types of mitral stenosis, which is a narrowing of the heart valve
- Idiopathic pediatric pulmonary arterial hypertension, which is an unusual form of high blood pressure in the lungs
- Pulmonary venous hypertension, also a type of high blood pressure in the lungs
- Total and partial anomalous pulmonary venous return, both of which mean the veins bringing blood from the lungs back to the heart aren’t connected right
- Atrial and ventricular septal defect, which are holes in the heart’s walls
- Idiopathic pulmonary hypertension, another unusual form of high blood pressure in the lungs
- Tricuspid stenosis, a narrowing of another heart valve
- Atrial myxoma, which is a type of heart tumor
A skilled surgical team should review any imagery of the heart that’s been taken. They can make a diagnosis faster, which can help prevent problems down the road.
Possible Complications When Diagnosed with Cor Triatriatum
Cor triatriatum can lead to a number of complications, such as:
- Failure of the right side of the heart
- Fluid buildup in the lungs / high blood pressure in the lungs
- Irregular heartbeats starting in the upper chambers of the heart
- Death
Preventing Cor Triatriatum
The care for cor triatriatum, a rare heart condition, typically involves a team of medical professionals. These include a pediatric cardiologist, who is a heart specialist for children; a pediatric cardiac surgeon, who performs heart surgery on kids; and an intensivist, a doctor who specializes in treating critically ill patients.