Definition

Ventricular Septal Defect (VSD) is a congenital condition where there is a hole between the left and right ventricles of the heart. This defect occurs in the wall (septum) that separates the lower chambers (ventricles) of the heart, allowing blood to flow from the left side to the right side. VSD typically develops during pregnancy when the wall between the two heart chambers does not fully form, leaving a hole. VSD is one of the types of congenital heart defects present from birth.

The CDC estimates that 42 out of every 10,000 babies are born with VSD. This translates to about 16,800 babies born with VSD each year in the United States, or approximately 1 in every 240 babies.

Babies with VSD can have one or more holes in different locations. Common types of VSD include:

• Conoventricular Ventricular Septal Defect: A hole located just below the pulmonary (lung) and aortic (main artery) valves.
• Perimembranous Ventricular Septal Defect: A hole in the upper section of the ventricular septum.
• Inlet Ventricular Septal Defect: A hole near where blood enters the ventricles via the tricuspid and mitral valves, sometimes part of a condition known as Atrioventricular Septal Defect (AVSD).
• Muscular Ventricular Septal Defect: A hole in the muscular lower part of the ventricular septum, the most common type of VSD.

Causes

Congenital heart defects often arise due to problems during early heart development, although the specific cause of VSD is often unknown. Genetics and environmental factors may play a role in the occurrence of VSD. VSD can occur on its own or alongside other congenital heart defects.

During fetal development, VSD occurs when the muscular wall that separates the left and right sides of the heart (septum) fails to fully form between the lower chambers. Normally, the right side of the heart pumps blood to the lungs to receive oxygen, while the left side pumps oxygen-rich blood to the body. VSD allows oxygenated blood to mix with deoxygenated blood, increasing blood pressure and flow to the pulmonary arteries, causing additional strain on the heart and lungs.

Risk Factor

VSD often occurs alongside other congenital birth defects. Factors that increase the risk of other congenital defects can also increase the risk of VSD, including:

• Asian heritage
• Family history of congenital heart disease
• Genetic disorders like Down syndrome

Symptoms

VSD often occurs alongside other congenital birth defects. Factors that increase the risk of other congenital defects can also increase the risk of VSD, including:

• Asian heritage
• Family history of congenital heart disease
• Genetic disorders like Down syndrome

In infants, moderate to large VSD causes symptoms that look like heart failure, including:

• Shortness of breath, including fast breathing or difficulty breathing.
• Sweating or tired of breastfeeding.
• Failed to grow (slow weight gain).
• Respiratory tract infections that often occur.

VSD in larger children and adults can lead to the following:

• Feeling tired or easily running out of breath while exercising.
• It has a slightly higher risk of developing heart inflammation caused by infection.
• The skin that is very pale or bluish on the skin and lips (conditions called cyanosis) can occur.

Diagnosis

To diagnose VSD, the doctor will start with an interview with the parents or caregivers about the baby's symptoms, when they began, and if any other congenital conditions are present. The doctor will then perform a physical exam, particularly listening to the baby's heart with a stethoscope. Additional tests may include:

• Echocardiogram. Sound waves create a video image of the heart. This test helps diagnose VSD and determine its size, location, and severity. It can also detect other heart issues. Fetal echocardiography can be used to diagnose VSD in unborn babies.
• Electrocardiogram (ECG). This test records the heart’s electrical activity and helps identify heart abnormalities or irregular heart rhythms.
• Chest X-ray. X-ray images can show whether the heart is enlarged or if there is extra fluid in the lungs.
• Cardiac catheterization. A thin, flexible tube (catheter) is inserted into a blood vessel in the groin or arm and guided to the heart. This test helps diagnose congenital heart defects and assesses the function of the heart's chambers and valves.
• Pulse oximetry. A small clip on the finger measures the amount of oxygen in the blood.

Management

Most VSDs are too small to cause any problems and will likely close on their own by age 6. In these cases, the doctor may recommend monitoring the condition without surgery to see if the hole closes naturally. For larger VSDs, the doctor may suggest surgical repair to close the hole. Two main methods to repair VSD are

• Surgery: The most reliable way to close a VSD is by patching it during surgery. The surgeon may use a patch made from synthetic material or the patient’s own tissue.
• Transcatheter procedure: Similar to cardiac catheterization, this method uses a catheter-based approach to place a device called an occluder in the hole, which blocks it. The device is often made of mesh and covered with synthetic material.

In cases where a baby or child is not gaining weight or growing as expected, special nutritional interventions may be recommended, including special diets or feeding tubes.

Medication can help manage VSD symptoms before surgery or if the defect may close on its own over time. Common medications for VSD include:

• Diuretics: These medications help the kidneys remove excess fluid from the body.
• Heart failure medications: These drugs help control the heart's pumping strength and rhythm, such as digoxin, which is often used to treat heart failure and can also benefit VSD patients.

Complications

Small VSDs may not cause complications. However, moderate or large VSDs can lead to complications such as:

• Heart failure. The heart works harder, and the lungs receive too much blood. Without treatment, this leads to heart failure.
• Pulmonary hypertension. Increased blood flow to the lungs due to VSD can cause high blood pressure in the pulmonary arteries, leading to permanent damage. This can cause the blood flow to reverse (Eisenmenger syndrome).
• Endocarditis. A rare but serious heart infection.
• Other heart disorders. These can include abnormal heart rhythms and valve disorders.

Prevention

Since the exact cause of VSD is unknown, prevention is generally not possible. However, you can reduce risk by avoiding alcohol and certain anti-seizure medications during pregnancy.

When to See a Doctor?

Consult your doctor if your baby shows symptoms that may indicate VSD, so the underlying cause can be determined.