Ventricular Septal Defect: VSD Types, Causes, and Treatment

28 March,2024

Ventricular septal defect (VSD) is a heart ailment that has been present since birth. It is marked by an opening between the walls separating the heart's lower chambers (ventricles). Approximately 90% of VSDs resolve on their own during childhood. 

Treatment options for VSD that do not close on their own depend on the size and severity of the defect. Sometimes, the cardiologist may prescribe medication to manage symptoms and control blood pressure. However, if the defect is large and causes significant symptoms or complications, surgical intervention may be necessary to repair the hole in the septum.

Fortunately, advances in cardiac science have significantly improved the outcomes for individuals with a ventricular septal defect. With proper diagnosis, timely intervention, and ongoing medical care, VSD patients can lead fulfilling lives and enjoy good heart health.

What is a Ventricular Septal Defect?

Ventricular Septal Defect (VSD) is one of the most common congenital (birth) heart defects, affecting approximately 1 in 500 births. The heart comprises four chambers: the right atrium, left atrium, right ventricle, and left ventricle. The right and left ventricles have a wall separating them, known as the ventricular septum. VSDs are openings or holes in the ventricular septum, which leads to the blood mixing between both chambers.

The severity of a VSD depends on various factors, such as the location and size of the defect. Small VSDs may close on their own or cause minimal symptoms, while larger defects can lead to significant complications.

One potential complication of VSD is the development of pulmonary hypertension. When blood from the left ventricle flows into the right ventricle through the hole, excessive blood is sent to the lungs. In the long run, this increased blood flow leads to high blood pressure in the lungs, causing strain on the heart.

Types of Ventricular Septal Defects 

Based on the location and structure of the ventricular septal defect, VSDs are of 4 significant types.

• Conoventricular Ventricular Septal Defect: In conoventricular VSD, a hole is present just below the pulmonary and aortic valves.
• Perimembranous Ventricular Septal Defect: This is a hole in the upper part of the ventricular wall. It is one of the most common VSDs, responsible for 80% of the cases.
• Inlet Ventricular Septal Defect: In inlet VSD, a hole is present in the septum just below the tricuspid and mitral valves. It might also be part of another heart defect known as atrioventricular septal defect.
• Muscular Ventricular Septal Defect: A muscular ventricular septal defect (VSD) is a condition with a hole in the lower part of the ventricular septum. About 20% of VSDs in infants are muscular ventricular septal defects.

VSD Size and its Effect

Ventricular septal defects can range from small to large. The effect of VSD on the body is determined by its size.

• Small VSDs: Most ventricular septal defects are less than 3 mm in diameter and close on their own by age 6. No particular symptoms are present, and surgery is rarely needed. 
• Moderate VSDs: Ventricular septal defects of size 3-5 mm in diameter are moderate-sized VSDs. These VSDs do not typically show symptoms, and surgery can be delayed as there is a chance that some of them will close on their own.
• Large VSDs: Ventricular septal defects of 6 to 10 mm require surgical management. Without repair, large VSDs can cause permanent damage to the heart and lungs.

What Signs and Symptoms Does Ventricular Septal Defect Show?

Ventricular Septal Defect (VSD) is a condition that can display various symptoms depending on the size and location of the defect. Individuals with small VSDs may not experience symptoms in some cases, while those with more significant defects may exhibit noticeable signs.

Common symptoms of VSD in infants include:

• Heart Murmur 
• Difficulty feeding
• Poor weight gain
• Rapid breathing
• Excessive sweating

These symptoms occur because the hole in the septum allows blood to flow between the chambers, causing the heart to work harder to pump oxygenated blood throughout the body.
As children with VSD grow older, they may develop symptoms such as:

• Shortness of breath
• Fatigue
• Frequent respiratory infections
• Palpitations
• Chest pain
• Bluish discoloration of the skin

What are the Causes and Risk Factors for Ventricular Septal Defect?

Ventricular Septal Defect (VSD) is a congenital heart defect characterized by a septum hole separating the heart's two lower chambers. While the exact cause of VSD is unknown, multiple factors play a role in its development.

• Research and studies suggest that genetics and environmental factors can increase the likelihood of a child being born with VSD. 
• It has been observed that individuals with a family history of congenital heart defects are at a higher risk of having VSD themselves.
• Maternal exposure to certain drugs and infections during pregnancy is another possible cause of VSD. 
• Substance abuse, including alcohol or tobacco use, can also contribute to the development of this condition. 
• Additionally, certain medical conditions such as diabetes, rubella, or Down syndrome in the mother can increase the risk of VSD in the fetus.
• Recent studies have also highlighted the role of folate deficiency in the development of VSD. Folate, a B vitamin essential for DNA synthesis and repair, is crucial for proper fetal development. Insufficient folate levels in expectant mothers have been linked to an increased risk of VSD in their babies. 

It is important to note that while these factors may increase the likelihood of VSD, not everyone with these risk factors will have the defect. Furthermore, VSD can also occur in individuals with no known risk factors. Therefore, consulting with a healthcare professional for accurate information and guidance is crucial.

How is a Ventricular Septal Defect Diagnosed?

To diagnose VSD, a healthcare professional will typically perform a physical examination, listen for abnormal heart sounds (murmurs), and order additional tests such as an echocardiogram or cardiac catheterization. These tests provide detailed images of the heart, allowing the cardiologists to assess the size and severity of the defect.

• During a physical examination, the healthcare professional will carefully listen to the heart using a stethoscope. They will pay close attention to any abnormal heart sounds, known as murmurs, which can indicate the presence of a VSD. These murmurs are due to turbulent blood flow through the hole in the septum.
• In addition to the physical examination, an echocardiogram is a commonly used diagnostic tool for VSD. It is also known as heart ultrasound and uses sound waves to produce clear images of the heart. It allows the healthcare professional to visualize the defect and determine its size and location.
• Sometimes, the cardiologist will put multiple sensors on the chest's skin and record the heart's electrical activity. This procedure is known as an ECG or an electrocardiogram. VSD can change the heart structure and electrical patterns depicted in an ECG. 
• In some cases, a cardiac catheterization may be necessary to evaluate the VSD further. Catheterization involves inserting a flexible, thin tube called a catheter and guiding it to the heart. Contrast dye is also injected, which allows the healthcare professional to see the blood flow through the heart and identify abnormalities.

What are the Treatment Options for a Ventricular Septal Defect?

It is essential to diagnose and treat VSD early, as this condition can lead to complications such as heart failure, elevated blood pressure in the lungs, or infective endocarditis. With prompt medical intervention, individuals with VSD can often lead normal and healthy lives.

Treatment options for VSD depend on the size and severity of the defect. Small VSDs may sometimes close on their own as the child grows. However, larger defects may require surgical intervention to repair the hole in the septum. The specific surgical intervention will depend on the location and complexity of the defect. Surgical options for ventricular septal defect include – 

• Open Heart Surgery: An open heart surgery requires the patient to be put on a heart and lung machine until the surgeon operates. It involves making an incision in the chest and gaining access to the heart. The surgeon can either stitch the hole shut or use a patch to close the hole. The patch can be made of synthetic material or a graft of your own tissue. 
• Cardiac Catheterization: Transcatheter procedures involve using a catheter (thin, flexible tube) to repair the VSD. The catheter is inserted via a major artery and moved up to the defect. It then places an occluder (a specialized device with a mesh framework) to plug the hole. 

In both surgeries, the heart tissue grows over the patch or the occluding device and becomes part of the ventricular septum.

After surgery, individuals with VSD will require regular follow-up appointments to monitor their heart health. This may include echocardiograms, electrocardiograms, and other tests to ensure that the defect has been successfully repaired and that the heart is functioning correctly.

To Conclude

Ventricular Septal Defect (VSD), or a hole in the heart, is a congenital (birth) defect with an opening between the heart's lower chambers. Individuals with VSD need regular follow-up appointments with a cardiologist to monitor their heart health and promptly address potential issues. Small VSDs may not require treatment, and people can lead normal, healthy lives without restrictions. However, they must be aware of the signs and symptoms of complications, such as fatigue, rapid breathing, poor weight gain, and recurrent respiratory infections, which may indicate further evaluation and intervention.