What Is Ventricular Septal Defect?

Overview

Ventricular septal defect (VSD) is a type of heart defect that is present at birth (congenital). It causes an abnormal opening to form in the wall that separates two different sections of the heart. This can lead to a range of symptoms and often requires surgery. Following treatment, many children go on to lead healthy lives.

There are two chambers at the bottom of the heart. These chambers are known as ventricles. The left ventricle is filled with oxygen-rich blood, whereas the right ventricle contains blood that is oxygen-deficient. These ventricles are separated by a wall called the septum. A defect in this wall, such as a hole or gap, leads to blood mixing and causes blood to flow in the incorrect direction. This results in the heart working inefficiently.¹ 

This heart defect does not always present with symptoms. Yet, if the hole is large enough, it can cause a range of symptoms, such as difficulty breathing and weight gain. Depending on the severity of the defect, it may heal on its own or require surgical intervention. 

Types of ventricular septal defect

In order to clearly understand the different types of VSDs, they are organised into four key types. These types are based on their anatomical locations within the heart.² Although the table below shows the four key types, it is important to note that there may be slight variations in individual cases and not every patient will fall into a particular category perfectly.

Causes of ventricular septal defect

As with many health conditions, there is not a single cause that leads to the development of VSDs. Several factors contribute to the development of VSDs.

These factors are as follows:

• Genetic Factors
• Environmental Factors
• Structural defects
• Maternal Health
• Family History

Genetic Factors refer to factors such as an abnormal number of chromosomes (aneuploidy). Examples of this include Down Syndrome, Patau Syndrome, and Edwards Syndrome. People who suffer from these chromosomal genetic conditions often suffer from VSDs.⁴

Besides genetic factors, environmental factors also contribute to the development of congenital heart defects. Exposure to harmful air pollutants and other environmental factors is believed to play a role in the development of VSDs.

The maternal womb serves as the foetus’ (unborn baby) environment during its development, emphasising the significance of maternal health. Alcohol or drug consumption, as well as smoking, by the mother during pregnancy can have detrimental effects on foetal development, potentially resulting in VSDs.⁵

Alongside maternal health, family history is another important factor to consider when exploring the causes of VSDs and other congenital heart defects. However, it's crucial to emphasise that family members should not feel guilty if a relative is born with a congenital heart defect. While a family history of congenital heart defects may slightly increase the chances of a child having a VSD, it does not guarantee its occurrence.⁶

Signs and symptoms of ventricular septal defect

Signs and symptoms of VSDs can either be present at birth or may develop later in life. When the defect is more severe, such as the presence of a large hole or multiple holes in the septum, the symptoms are usually more pronounced. Younger children are also more prone to experiencing severe symptoms. In contrast, in less severe cases of VSDs, the condition may go unnoticed due to the absence of symptoms, often only being detected during a medical examination when a doctor identifies a heart murmur.

The signs and symptoms of VSDs differ between adults and children.

Symptoms in infants and children:

• Difficulty feeding or poor weight gain
• Rapid breathing or shortness of breath
• Sweating, particularly during feeding
• Fatigue or weakness
• Frequent respiratory infections
• Pale skin
• Heart murmur (a swishing or whooshing sound) detected by a doctor 

Symptoms in adults:

• Shortness of breath, especially during physical exertion
• Fatigue or weakness
• Palpitations or irregular heartbeat
• Dizziness or fainting
• Swelling in the legs, ankles, or feet
• Chest pain or discomfort

It's important to note that the severity of symptoms can vary depending on the size and location of the VSD. If you or your child experience any of these signs or symptoms, it is essential to consult your doctor for proper evaluation and guidance.

Management and treatment for ventricular septal defect

The management and treatment of a congenital heart defect is not a one-size-fits-all approach. A specialist doctor will develop a personalised treatment plan based on the specific type of VSD. The treatment for a VSD may involve a combination of approaches, including:

• Observation and monitoring
• Surgical repair
• Medication
• Catheter-based procedures
• Follow-up care

Larger VSDs cannot close naturally, so they will require surgical intervention. This surgical intervention reduces the risk of further complications, such as endocarditis (inflammation of your heart’s inner lining) and pulmonary arterial hypertension (increased blood pressure in the arteries of the lungs).⁷

On the other hand, a catheter-based procedure may be a suitable option. This is a minimally invasive technique where a small flexible tube is inserted into the body via a small hole or incision. An example of this is percutaneous device closure. It  is a non-surgical option to fix the hole in the heart, which can be a good alternative when surgery is risky or not possible. This is typically a suitable option for muscular VSDs and has previously shown good outcomes with low mortality rates.⁸

However, complications with this procedure may include the development of a complete atrioventricular block. Essentially this means that the electrical signals that control the heartbeat cannot pass properly between the upper and lower chambers of the heart.²

Diagnosis of ventricular septal defect

If your child shows signs and symptoms of VSD, contact your doctor. The doctor will conduct the appropriate examination by listening for a heart murmur and then following up with an echocardiogram and potentially an ultrasound to assess the size and severity of the defect.

An echocardiogram is a non-invasive test that uses sound waves to create detailed pictures of the heart. It helps the doctor see the structures inside the heart and check for any abnormalities, such as VSD.⁹

Similarly, an ultrasound is a painless test that uses sound waves to create images of different parts of the body. In this case, the doctor will use an ultrasound to look closely at the heart and gather more information about the VSD.

Risk factors

Heart defects in babies are believed to result from several genetic and environmental factors. These include: 

• Substances the mother uses during pregnancy
• The mother’s diet
• Alcohol or drug consumption
• Certain medications

By identifying and addressing these risk factors, we can work towards better outcomes and reduce the likelihood of developing VSDs.

FAQs

How can I prevent ventricular septal defect?

Currently, there are no ways to prevent the occurrence of this congenital defect. However, by following medical advice during pregnancy, it is possible to minimise some of the risks that contribute to the development of VSD.

How common is ventricular septal defect?

According to the Centers for Disease Control and Prevention, approximately 1 in 240 babies are born with a VSD each year.

When should I see a doctor?

If your child is experiencing any symptoms, such as trouble breathing or chest pain, contact your local emergency care provider immediately. If you suspect VSD, contact your general doctor or obtain a referral to a cardiologist (a doctor who specialises in treating heart diseases).

Summary

In summary, ventricular septal defects (VSDs) are classified into different types based on their location in the heart. Genetic and environmental factors, maternal health during pregnancy, and family history can contribute to the development of VSDs. Symptoms vary among infants, children, and adults. Treatment options include surgical repair and catheter-based procedures. Diagnosing VSD involves a thorough examination, an echocardiogram, and an ultrasound. While prevention methods are not currently available, following medical advice during pregnancy can help reduce associated risks.