VENTRICULAR SEPTAL DEFECT (VSD)

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Imagine that the heart has two lower chambers separated by a wall. A ventricular septal defect (VSD) is a hole in this wall, allowing oxygen-rich blood to mix with oxygen-poor blood. This defect usually develops before birth and is most common in babies. The ventricles are the heart’s lower chambers, and the wall separating them is called the septum. When there’s a hole in this septum, it’s termed a septal defect.

Healthy hearts have a specific blood flow pattern:

• Blood returns to the right atrium from the body.
• It then moves to the right ventricle and lungs for oxygen.
• Oxygen-rich blood travels back to the left atrium, then to the left ventricle.
• Finally, the left ventricle pumps this blood throughout the body.

But a ventricular septal defect disrupts this flow:

• Oxygen-rich blood leaks from the stronger left ventricle to the weaker right ventricle, mixing with oxygen-poor blood.
• This forces the ventricles to pump harder, eventually straining the left ventricle and potentially leading to heart failure.
• Heart failure can cause fluid buildup in the lungs and body, and in severe cases, high pressure in the lungs (pulmonary hypertension).

The size of the hole and the infant’s lung function determine the severity. VSDs might not be heard initially but become detectable later due to changes in the circulatory system.

These defects are the most common congenital heart defect in infants, affecting roughly 25% of those born with heart problems, and are more frequent in premature babies.

Ventricular Septal Defect Causes

The exact cause of ventricular septal defects remains unknown, but they likely stem from abnormalities in heart development during fetal growth.

• These defects can vary, with either a single or multiple holes present in the septum.
• The septum itself comprises several areas, including the membranous part, muscular part, and other segments known as the inlet and outlet. Any of these sections can develop a hole.
• The location of the hole depends on where the malformation occurs during fetal development.
• The most common type is the membranous variant, where the hole is situated below the aortic valve, regulating blood flow from the left ventricle into the body’s main artery, the aorta.

Ventricular Septal Defect Symptoms

• Small holes in the ventricular septum usually go unnoticed, but a healthcare provider can detect them during a checkup by listening for a loud heart murmur on the left side of the lower breastbone (sternum).
• Larger holes often lead to symptoms within 1–6 months after birth. As the left ventricle begins to struggle, symptoms such as rapid breathing, sweating, paleness, fast heartbeats, reduced feeding, and poor weight gain may occur.
• If left undetected and untreated, ventricular septal defects can lead to more severe issues over time, such as pulmonary hypertension. If the defect isn’t closed surgically, irreversible pulmonary hypertension may develop, and surgery might no longer be beneficial.
• Typical symptoms of pulmonary hypertension include fainting, shortness of breath, chest pain, and a bluish discoloration of the skin known as cyanosis, indicating insufficient oxygen reaching the tissues, a condition termed “hypoxemia” or “hypoxia.”

When to Seek Medical Attention

It’s essential to notify your child’s healthcare provider if you observe any of the following:

• Poor weight gain or a slowdown in weight gain during the initial months of life.
• Unusual behaviors or any symptoms mentioned earlier. Immediate medical attention at the nearest hospital emergency department is necessary if you notice:
• Shortness of breath, difficulty breathing, or worsening of existing breathing difficulties.
• Bluish discoloration of the skin, lips, or under the nails.
• Unusual or unexplained sweating.

Examinations and tests for ventricular septal defect (VSD)

If a ventricular septal defect is identified before your baby is discharged from the hospital, several tests may be conducted:

• An echocardiogram (a heart ultrasound), a chest X-ray, and blood tests.
• You’ll be advised to follow up with your child’s primary care provider and to monitor closely for signs of congestive heart failure or hypoxia.
• During a physical exam, a doctor can often detect a ventricular septal defect (hole in the heart’s wall) by listening to your chest with a stethoscope. They’ll be looking for a specific sound called a systolic murmur along the lower left border of your breastbone. This murmur happens because oxygen-rich blood is whooshing through the hole in the heart wall and into the right ventricle where it shouldn’t be.
• An echocardiogram can confirm the presence of a hole in the heart. This painless test uses ultrasound waves to create a moving picture of the heart, measuring the size of the left-to-right shunt, left ventricle enlargement, and estimating the shunting degree.
• A chest X-ray helps assess overall heart size and detect fluid in the lungs or pulmonary congestion. An electrocardiogram can evaluate the sizes of the left and right ventricles, potentially indicating pulmonary hypertension if right ventricular hypertrophy is present.
• Cardiac catheterization may be necessary in certain cases. This involves inserting a thin tube called a catheter into the skin, typically in the groin, arm, or neck, and advancing it to the heart under X-ray guidance. Doctors measure pressures inside the heart, especially if they’re worried about pulmonary hypertension or whether surgery is possible. They might also inject a dye to see the heart’s anatomy in more detail, but an echocardiogram usually gives enough information for most patients.

Treatment of Ventricular Septal Defects

• Some children may have their ventricular septal defects close on their own as they grow.
• For larger defects causing symptoms, doctors take action. They prescribe medications to ease congestive heart failure symptoms like poor growth, sweating, and rapid breathing. Antibiotics become a routine precaution for dental work or any invasive procedures if the hole in the heart hasn’t closed yet.
• Surgery is necessary for larger defects that do not close spontaneously. Doctors typically perform surgery before the child starts preschool. Surgery becomes necessary if medications aren’t effective in managing symptoms, especially when there’s evidence of developing pulmonary hypertension.. The most common surgical method involves placing a patch over the hole.
• Doctors are pioneering a new approach: using devices delivered through a cardiac catheterization lab to cover VSDs, eliminating the need for open-heart surgery.

Next Steps and Follow-Up

• Regular office visits and echocardiograms are necessary to monitor the ventricular septal defect.
• Weight, Height, Feeding, and Activity: Doctors will regularly check your child’s weight, height, feeding habits, and activity level to monitor their development.
• Antibiotics for Procedures: Children with VSDs will typically receive antibiotics before dental work or any invasive surgery as a preventive measure.

Prevention and Outlook

• Pregnant women cannot prevent ventricular septal defects.
• Many defects close on their own as the child grows, and those that don’t may require medical intervention.
• Kids with mild to moderate blood flow issues might need to slow down. But once the hole is fixed, they can play freely!
• Complications such as aortic regurgitation, endocarditis, and pulmonary hypertension may arise from ventricular septal defects.

Complications Associated with Ventricular Septal Defects

1. Aortic regurgitation: this happens when blood leaks back from the aorta, straining the heart and hindering circulation.
2. Endocarditis: This is an infection of the heart valves resulting from abnormal blood flow. Due to the risk of endocarditis, healthcare professionals may recommend antibiotic prophylaxis before dental procedures or surgeries for children with certain types of ventricular septal defects.
3. Pulmonary hypertension: This condition develops when blood flow gets rerouted. Normally, blood flows from the left ventricle to the lungs. But with a ventricular septal defect (VSD), blood leaks from the left ventricle back to the right ventricle. This extra blood flow increases pressure in both the right ventricle and the lungs, leading to pulmonary hypertension.

Synonyms and Keywords:

Ventricular septal defect, atrial septal defect, congenital heart defect, heart murmur, hole in the heart, leaking heart, left-to-right shunt, VSD, aortic regurgitation, endocarditis, pulmonary hypertension.

Sources:

“Ventricular Septal Defect” by eMedicineHealth.

Ventricular Septal Defect” Webmd