About Ventricular Septal Defect

What it is

A ventricular septal defect (VSD) happens during pregnancy if the wall that forms between the two ventricles does not fully develop. This leaves a hole.

In babies without a heart defect, the right side of the heart pumps oxygen-poor blood from the heart to the lungs. The left side of the heart pumps oxygen-rich blood to the rest of the body. In babies with a VSD, blood flows from the left ventricle through the VSD to the right ventricle into the lungs.

Occurrence

About 42 of every 10,000 babies in the United States are born with a VSD.1 This means that about 16,800 babies are born with a VSD each year.

Types

An infant with a VSD can have one or more holes in different places of the septum. There are several names for these holes. Some common locations and names are listed below:

Conoventricular Ventricular Septal Defect. In general, this is a hole where portions of the ventricular septum should meet just below the pulmonary and aortic valves.

Perimembranous Ventricular Septal Defect. This is a hole in the upper section of the ventricular septum.

Inlet Ventricular Septal Defect. This is a hole in the septum near to where the blood enters the ventricles through the tricuspid and mitral valves. This type of ventricular septal defect also might be part of another heart defect called an atrioventricular septal defect (AVSD).

Muscular Ventricular Septal Defect. This is a hole in the lower, muscular part of the ventricular septum. This is the most common type of ventricular septal defect.

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Signs and symptoms

The size of the ventricular septal defect will influence what symptoms, if any, are present.

Signs of a ventricular septal defect might be present at birth or might not appear until well after birth. If the hole is small, it could close on its own. The baby might not show any signs of the defect. However, if the hole is large, the baby might have symptoms, including

• Shortness of breath
• Fast or heavy breathing
• Sweating
• Tiredness while feeding
• Poor weight gain

Complications

A ventricular septal defect increases the amount of blood that flows through the lungs. This forces the heart and lungs to work harder. Overtime, if not repaired, a ventricular septal defect can increase the risk for other complications, including

• Heart failure
• High blood pressure in the lungs (called pulmonary hypertension)
• Irregular heart rhythms (called arrhythmia)
• Stroke

Risk factors

The causes of ventricular septal defects among most babies are unknown. Some babies have heart defects because of changes in their genes or chromosomes. A combination of genes and other risk factors may increase the risk for ventricular septal defects. These factors can include things in a mother's environment, what she eats or drinks, or the medicines she uses.

Diagnosis

A VSD is usually diagnosed after a baby is born. During a physical exam, a healthcare provider might hear a distinct whooshing sound, called a heart murmur. The size of the VSD will influence whether a healthcare provider hears a heart murmur during a physical exam.

If signs or symptoms are present, the healthcare provider might request one or more tests to confirm the diagnosis. The most common test is an echocardiogram, which is an ultrasound of the heart. An echocardiogram can show how large the hole is and how much blood is flowing through the hole.

Treatments

Treatments for a VSD depend on the size of the hole and the problems it might cause. Many VSDs are small and close on their own. If the hole is small and causing no symptoms, the doctor will check the infant regularly. This is to ensure there are no signs of heart failure and that the hole closes. If the hole doesn't close on its own or if it's large, further action might be needed.

Depending on the child's general health, symptoms, and the hole's size, the doctor might recommend cardiac catheterization or open-heart surgery. These procedures will close the hole and restore normal blood flow. After surgery, the doctor will set up regular follow-up visits to make sure that the VSD remains closed.

Medicines

Some babies and children will need medicines to help:

• Strengthen the heart muscle
• Lower their blood pressure
• Help the body get rid of extra fluid

Nutrition

Some babies with a ventricular septal defect become tired while feeding and do not eat enough to gain weight. To make sure babies have a healthy weight gain, a special high-calorie formula might be prescribed. Some babies become extremely tired while feeding and might need to be fed through a feeding tube.

What to expect long-term

Most children who have a VSD that closes (either on its own or with surgery) live healthy lives.