Diseases and ConditionsMay 31, 2025🔄 Updated: Jul 12, 2026⏱ 9 min

Is there a slight change in the blood flow in your heart? Let's talk about (Cardiac Shunt)!

Creator: Dr. Priya Sammani
Published: 2025-05-31T15:13:26.000Z

Dr. Priya Sammani, MBBS, PG Dip. FMMedical Verification

Our heart is an amazing organ, isn't it? But sometimes there can be small changes or disturbances in the way blood flows through the heart. Today we are going to talk about such a condition, that is, a `(Cardiac Shunt)` . This can be something that is born in some people, that is, as a `(Congenital Heart Defect)` . Some people may not have any symptoms, but for others, this can be a little more serious.

Let's first see how blood moves in the heart?

Simply put, our heart is like a house with four rooms. The right side of this is where the blood that has been used by the whole body, which has lost oxygen, collects. Then the heart sends this blood to the lungs. Think of it like sending it to a service station. It is in the lungs that new oxygen is added to this blood, just like putting gasoline in a car. At the same time, the carbon dioxide gas in the blood is removed . Now this oxygen-rich, clean blood comes back to the left side of the heart. From there, the heart distributes this blood to the whole body. This is helped by the large blood vessel called `(Aorta)` . This is how blood normally travels:

Oxygen-poor blood flows to the right side of the heart.
The heart pumps that blood to the lungs.
The lungs fill the blood with oxygen and remove carbon dioxide.
Oxygen-rich blood comes from the lungs to the left side of the heart.
The heart pumps this blood throughout the body.

Now, a `(Cardiac Shunt)` means that there is some kind of abnormality in the way the blood flows. That is, the blood does not flow from one place to another (a blood vessel or a heart chamber) in the normal way, but through a different path. Because of this, oxygenated blood can go back to the lungs, or oxygenated blood can go directly to the body without going to the lungs. Do you understand?

What are the main types of Cardiac Shunt?

There are two main types of `(Cardiac Shunt)`, which are distinguished according to the direction of blood flow: 1. Left-to-right shunt (Left-to-right shunt / Acyanotic): In this, blood that has already received oxygen, that is, blood that should go to the body from the left side of the heart, leaks back through the right side to the lungs. In this , there is usually no decrease in oxygen levels (blueness) in the early stages. Some examples are:

Atrial Septal Defect (ASD): A hole between the two upper chambers (atria) of the heart.
Ventricular Septal Defect (VSD): A hole between the two lower chambers (chambers) of the heart.
Patent Ductus Arteriosus (PDA): A blood vessel that is present in the womb and should close after birth, remains open.
Atrioventricular Septal Defect: A complex defect in the walls between the atria and ventricles.
`(Total/Partial Anomalous Pulmonary Venous Return - TAPVR/PAPVR)`:Incorrect connection of the blood vessel (pulmonary vein) that brings oxygen from the lungs to the heart.

2. Right-to-left shunt (Cyanotic): This is when oxygen-poor blood from the body does not go to the lungs to pick up oxygen, but instead goes straight to the left side of the heart and circulates throughout the body. This causes the oxygen level in the blood to decrease, and the skin may appear blue . This is called `(Cyanosis)` . Some examples:

Tetralogy of Fallot: This is a combination of four heart defects.
Transposition of the Great Arteries: The position of the two main blood vessels that carry blood from the heart to the body and lungs is reversed.
Pulmonary Atresia: The valve that carries blood to the lungs (pulmonary valve) is not properly formed.
Eisenmenger Syndrome: A shunt that was originally from left to right eventually turns from right to left.
Hypoplastic Left Heart Syndrome ( HLHS ): The left side of the heart does not develop properly.
`(Double Outlet Right Ventricle)`
`(Pulmonary Arteriovenous Malformation)`
`(Truncus Arteriosus)`

In addition, there is a condition called a circular shunt . This is a very serious, life-threatening condition. In this case, blood circulates within the heart, but not enough blood is pumped to the body. This is most often seen in severe cases of a condition called `(Ebstein's Anomaly - EA)` .

How common are these (Cardiac Shunt) conditions?

In fact, this `(Cardiac Shunt)` is the most common type of congenital heart defect . On average , about one in every 100 babies may have some type of congenital heart defect.

What are the causes of (Cardiac Shunt)?

Sometimes these can be caused by a genetic component . That is, it can be caused by a change (`(Mutation)`) in a certain gene. For example, about half of people with `(Down Syndrome)` have some type of `(Cardiac Shunt)`. Also, certain things that affect the mother during pregnancy can increase the risk of the baby developing `(Cardiac Shunt)`.

The mother has ``(Gestational Diabetes )`` ( diabetes during pregnancy).
Excessive use of the painkiller ``( Ibuprofen )`` or vitamin A.
Influenza (flu) .
Marijuana use .
Rubella (German Measles)

Just think, if a mother is exposed to something like this during pregnancy, it could have a small effect on the baby's heart development. That's why it's important to be very careful during pregnancy.

What are the symptoms of a Cardiac Shunt?

Symptoms can vary greatly. Left-to-right shunts often go undetected until adolescence or adulthood . If symptoms do occur, they may include:
Difficulty breathing (Dyspnea) .
Feeling tired quickly, unable to exercise.
Over time, this left-to-right shunt can cause pulmonary hypertension (high blood pressure in the blood vessels of the lungs). In right-to-left shunts , symptoms usually begin in infancy .
The main symptom is a blue coloration of the baby's skin (cyanosis) .
Clubbed fingers or toenails .
Coughing up blood (Hemoptysis) .
The baby is not gaining weight properly .
Difficulty breathing (Dyspnea) .
Frequent infections .
Imagine how scary it would be for a mother or father to see a newborn baby turning blue. The most important thing in times like these is to see a doctor as soon as possible.
How do you find out if you have a (Cardiac Shunt)?
If a doctor suspects a cardiac shunt, they may perform several tests, such as:
Blood test : Look for changes in red blood cells.
Imaging tests: Take a chest X-ray or CT scan to look for changes in the shape of the heart.
Echocardiogram: This is like an ultrasound scan of the heart. It can look at the structure of the heart , how it works, how it flows, and whether there are any holes. This is often the most important test.
Electrocardiogram - EKG: To check the electrical activity of the heart and detect conditions such as Pulmonary Hypertension.
Cardiac Catheterization: This test measures the pressure inside each chamber of the heart. It can be used to decide whether surgery is needed or to help determine if surgery is already recommended.
How is Cardiac Shunt treated?
Treatment depends on the symptoms and severity of the condition. Some small shunts may heal on their own without any treatment. For larger shunts, doctors may perform surgery to correct the bleeding path . Some common surgeries include:
`(Norwood procedure)`: This is an open-heart surgery usually performed on newborn babies. Here, surgeons create a large `(Aorta)` and change the blood flow path. After the surgery, the right ventricle is able to do its job of pumping blood to the body.
`(Glenn procedure)`: The surgeon changes the blood flow path and directs blood from the body directly to the lungs.
`(Fontan procedure)`: In this procedure, the blood flow is also changed and the oxygen-poor blood is sent directly to the lungs. After the surgery, the oxygen-rich blood goes directly to one of the heart chambers. This prevents the mixing of oxygen-poor and oxygen-rich blood in the heart chambers.
Hearing about these surgeries can be scary, but they have saved the lives of many babies.
Can a Cardiac Shunt be prevented?
There is no 100% surefire way to prevent a cardiac shunt. However, if you are pregnant, you can follow healthy habits to increase your overall chances of having a healthy baby:
Avoid harmful substances: Avoid alcohol, tobacco, illegal drugs, and excessive amounts of caffeine.
Eat a nutritious diet: Avoid foods that can increase the risk of infection, such as undercooked meat, some types of cheese, and unpasteurized animal products.
Exercise regularly .
Get all vaccinations as recommended by your doctor, including the flu shot.
Get at least seven to eight hours of sleep a night. Try to sleep on your left side to increase blood circulation.
Take prenatal vitamins and other nutritional supplements as directed by your doctor.
What is the outlook for someone with a (Cardiac Shunt)?
This also varies greatly depending on the type and severity of the `(Cardiac Shunt)`. Large or severe `(Cardiac Shunt)` requires treatment to prevent complications. Some types may require surgical treatment within a few weeks of birth . If you have severe `(Pulmonary Hypertension),` you are more likely to need heart surgery or develop complications. In most cases, shunts that do not significantly affect the oxygen level in the blood do not cause serious complications. They may not show any symptoms or require any treatment.
What else do you want to ask your doctor?
If you or your baby has a ``Cardiac Shunt'', it's a good idea to ask your doctor about the following:
What type of `(Cardiac Shunt)` does my/my baby have?
What tests do I/my baby need to have to find this out?
What treatment options are there?
What can I do to reduce the risk of complications from this `(Cardiac Shunt)`?
What are the chances that my next baby will also have a `(Cardiac Shunt)`?
What can we expect in the future?
Finally, take-home message:
A cardiac shunt is an abnormality in the way blood flows through your heart. These are often caused by genetic factors, but some are also related to factors that affect your pregnancy. The symptoms of a shunt vary greatly. Some types of shunts have very few or no symptoms. Others are serious and can be life-threatening if left untreated. If a cardiac shunt is severe, your doctor may perform surgery to create a new path for blood to flow.
Remember, if you or your baby have any of these symptoms, it's important to seek medical advice without panicking. Early diagnosis and proper treatment can lead to very good outcomes.
` Heart shunt, cardiac shunt, congenital heart disease, blood circulation, heart disease symptoms, pediatric heart disease, heart surgery

⚠️ Important: The medical articles and information on Nirogi Lanka are for general awareness only, and are by no means a substitute for professional medical advice, diagnosis, or treatment. For any medical problem you have, consult a qualified physician immediately.

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Diseases and ConditionsMay 31, 2025
Is there a slight change in the blood flow in your heart? Let's talk about (Cardiac Shunt)!
Dr. Priya SammaniMedical Verification
⏱ 9 min read
📋Table of Contents
1. Let's first see how blood moves in the heart?
2. What are the main types of Cardiac Shunt?
3. How common are these (Cardiac Shunt) conditions?
4. What are the causes of (Cardiac Shunt)?
5. What are the symptoms of a Cardiac Shunt?
6. How do you find out if you have a (Cardiac Shunt)?
7. How is Cardiac Shunt treated?
8. Can a Cardiac Shunt be prevented?
9. What is the outlook for someone with a (Cardiac Shunt)?
10. What else do you want to ask your doctor?
11. Finally, take-home message:
Our heart is an amazing organ, isn't it? But sometimes there can be small changes or disturbances in the way blood flows through the heart. Today we are going to talk about such a condition, that is, a `(Cardiac Shunt)` . This can be something that is born in some people, that is, as a `(Congenital Heart Defect)` . Some people may not have any symptoms, but for others, this can be a little more serious.
Let's first see how blood moves in the heart?
Simply put, our heart is like a house with four rooms. The right side of this is where the blood that has been used by the whole body, which has lost oxygen, collects. Then the heart sends this blood to the lungs. Think of it like sending it to a service station. It is in the lungs that new oxygen is added to this blood, just like putting gasoline in a car. At the same time, the carbon dioxide gas in the blood is removed . Now this oxygen-rich, clean blood comes back to the left side of the heart. From there, the heart distributes this blood to the whole body. This is helped by the large blood vessel called `(Aorta)` . This is how blood normally travels:
Oxygen-poor blood flows to the right side of the heart.
The heart pumps that blood to the lungs.
The lungs fill the blood with oxygen and remove carbon dioxide.
Oxygen-rich blood comes from the lungs to the left side of the heart.
The heart pumps this blood throughout the body.
Now, a `(Cardiac Shunt)` means that there is some kind of abnormality in the way the blood flows. That is, the blood does not flow from one place to another (a blood vessel or a heart chamber) in the normal way, but through a different path. Because of this, oxygenated blood can go back to the lungs, or oxygenated blood can go directly to the body without going to the lungs. Do you understand?
What are the main types of Cardiac Shunt?
There are two main types of `(Cardiac Shunt)`, which are distinguished according to the direction of blood flow: 1. Left-to-right shunt (Left-to-right shunt / Acyanotic): In this, blood that has already received oxygen, that is, blood that should go to the body from the left side of the heart, leaks back through the right side to the lungs. In this , there is usually no decrease in oxygen levels (blueness) in the early stages. Some examples are:
Atrial Septal Defect (ASD): A hole between the two upper chambers (atria) of the heart.
Ventricular Septal Defect (VSD): A hole between the two lower chambers (chambers) of the heart.
Patent Ductus Arteriosus (PDA): A blood vessel that is present in the womb and should close after birth, remains open.
Atrioventricular Septal Defect: A complex defect in the walls between the atria and ventricles.
`(Total/Partial Anomalous Pulmonary Venous Return - TAPVR/PAPVR)`:Incorrect connection of the blood vessel (pulmonary vein) that brings oxygen from the lungs to the heart.
2. Right-to-left shunt (Cyanotic): This is when oxygen-poor blood from the body does not go to the lungs to pick up oxygen, but instead goes straight to the left side of the heart and circulates throughout the body. This causes the oxygen level in the blood to decrease, and the skin may appear blue . This is called `(Cyanosis)` . Some examples:
Tetralogy of Fallot: This is a combination of four heart defects.
Transposition of the Great Arteries: The position of the two main blood vessels that carry blood from the heart to the body and lungs is reversed.
Pulmonary Atresia: The valve that carries blood to the lungs (pulmonary valve) is not properly formed.
Eisenmenger Syndrome: A shunt that was originally from left to right eventually turns from right to left.
Hypoplastic Left Heart Syndrome ( HLHS ): The left side of the heart does not develop properly.
`(Double Outlet Right Ventricle)`
`(Pulmonary Arteriovenous Malformation)`
`(Truncus Arteriosus)`
In addition, there is a condition called a circular shunt . This is a very serious, life-threatening condition. In this case, blood circulates within the heart, but not enough blood is pumped to the body. This is most often seen in severe cases of a condition called `(Ebstein's Anomaly - EA)` .
How common are these (Cardiac Shunt) conditions?
In fact, this `(Cardiac Shunt)` is the most common type of congenital heart defect . On average , about one in every 100 babies may have some type of congenital heart defect.
What are the causes of (Cardiac Shunt)?
Sometimes these can be caused by a genetic component . That is, it can be caused by a change (`(Mutation)`) in a certain gene. For example, about half of people with `(Down Syndrome)` have some type of `(Cardiac Shunt)`. Also, certain things that affect the mother during pregnancy can increase the risk of the baby developing `(Cardiac Shunt)`.
The mother has ``(Gestational Diabetes )`` ( diabetes during pregnancy).
Excessive use of the painkiller ``( Ibuprofen )`` or vitamin A.
Influenza (flu) .
Marijuana use .
Rubella (German Measles)
Just think, if a mother is exposed to something like this during pregnancy, it could have a small effect on the baby's heart development. That's why it's important to be very careful during pregnancy.
What are the symptoms of a Cardiac Shunt?
Symptoms can vary greatly. Left-to-right shunts often go undetected until adolescence or adulthood . If symptoms do occur, they may include:
Difficulty breathing (Dyspnea) .
Feeling tired quickly, unable to exercise.
Over time, this left-to-right shunt can cause pulmonary hypertension (high blood pressure in the blood vessels of the lungs). In right-to-left shunts , symptoms usually begin in infancy .
The main symptom is a blue coloration of the baby's skin (cyanosis) .
Clubbed fingers or toenails .
Coughing up blood (Hemoptysis) .
The baby is not gaining weight properly .
Difficulty breathing (Dyspnea) .
Frequent infections .
Imagine how scary it would be for a mother or father to see a newborn baby turning blue. The most important thing in times like these is to see a doctor as soon as possible.
How do you find out if you have a (Cardiac Shunt)?
If a doctor suspects a cardiac shunt, they may perform several tests, such as:
Blood test : Look for changes in red blood cells.
Imaging tests: Take a chest X-ray or CT scan to look for changes in the shape of the heart.
Echocardiogram: This is like an ultrasound scan of the heart. It can look at the structure of the heart , how it works, how it flows, and whether there are any holes. This is often the most important test.
Electrocardiogram - EKG: To check the electrical activity of the heart and detect conditions such as Pulmonary Hypertension.
Cardiac Catheterization: This test measures the pressure inside each chamber of the heart. It can be used to decide whether surgery is needed or to help determine if surgery is already recommended.
How is Cardiac Shunt treated?
Treatment depends on the symptoms and severity of the condition. Some small shunts may heal on their own without any treatment. For larger shunts, doctors may perform surgery to correct the bleeding path . Some common surgeries include:
`(Norwood procedure)`: This is an open-heart surgery usually performed on newborn babies. Here, surgeons create a large `(Aorta)` and change the blood flow path. After the surgery, the right ventricle is able to do its job of pumping blood to the body.
`(Glenn procedure)`: The surgeon changes the blood flow path and directs blood from the body directly to the lungs.
`(Fontan procedure)`: In this procedure, the blood flow is also changed and the oxygen-poor blood is sent directly to the lungs. After the surgery, the oxygen-rich blood goes directly to one of the heart chambers. This prevents the mixing of oxygen-poor and oxygen-rich blood in the heart chambers.
Hearing about these surgeries can be scary, but they have saved the lives of many babies.
Can a Cardiac Shunt be prevented?
There is no 100% surefire way to prevent a cardiac shunt. However, if you are pregnant, you can follow healthy habits to increase your overall chances of having a healthy baby:
Avoid harmful substances: Avoid alcohol, tobacco, illegal drugs, and excessive amounts of caffeine.
Eat a nutritious diet: Avoid foods that can increase the risk of infection, such as undercooked meat, some types of cheese, and unpasteurized animal products.
Exercise regularly .
Get all vaccinations as recommended by your doctor, including the flu shot.
Get at least seven to eight hours of sleep a night. Try to sleep on your left side to increase blood circulation.
Take prenatal vitamins and other nutritional supplements as directed by your doctor.
What is the outlook for someone with a (Cardiac Shunt)?
This also varies greatly depending on the type and severity of the `(Cardiac Shunt)`. Large or severe `(Cardiac Shunt)` requires treatment to prevent complications. Some types may require surgical treatment within a few weeks of birth . If you have severe `(Pulmonary Hypertension),` you are more likely to need heart surgery or develop complications. In most cases, shunts that do not significantly affect the oxygen level in the blood do not cause serious complications. They may not show any symptoms or require any treatment.
What else do you want to ask your doctor?
If you or your baby has a ``Cardiac Shunt'', it's a good idea to ask your doctor about the following:
What type of `(Cardiac Shunt)` does my/my baby have?
What tests do I/my baby need to have to find this out?
What treatment options are there?
What can I do to reduce the risk of complications from this `(Cardiac Shunt)`?
What are the chances that my next baby will also have a `(Cardiac Shunt)`?
What can we expect in the future?
Finally, take-home message:
A cardiac shunt is an abnormality in the way blood flows through your heart. These are often caused by genetic factors, but some are also related to factors that affect your pregnancy. The symptoms of a shunt vary greatly. Some types of shunts have very few or no symptoms. Others are serious and can be life-threatening if left untreated. If a cardiac shunt is severe, your doctor may perform surgery to create a new path for blood to flow.
Remember, if you or your baby have any of these symptoms, it's important to seek medical advice without panicking. Early diagnosis and proper treatment can lead to very good outcomes.
` Heart shunt, cardiac shunt, congenital heart disease, blood circulation, heart disease symptoms, pediatric heart disease, heart surgery
⚠️ Important: The medical articles and information on Nirogi Lanka are for general awareness only, and are by no means a substitute for professional medical advice, diagnosis, or treatment. For any medical problem you have, consult a qualified physician immediately.
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