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Ventricular septal defect describes one or more holes in the wall that separates the right and left ventricles of the heart. Ventricular septal defect is one of the most common congenital (present from birth) heart defects. It may occur by itself or with other congenital diseases.

VSD; Interventricular septal defect

Before a baby is born, the right and left ventricles of its heart are not separate. As the fetus grows, a wall forms to separate these two ventricles. If the wall does not completely form, a hole remains. This hole is known as a ventricular septal defect, or a VSD.

Ventricular septal defect is the most common congenital heart defect. The baby may have no symptoms, and the hole can eventually close as the wall continues to grow after birth.

If the hole is large, too much blood will be pumped to the lungs, leading to heart failure. These babies often have symptoms related to heart failure and may need medicine to control the symptoms and surgery to close the hole. The hole can also be closed without surgery, through cardiac catheterization.

The cause of VSD is not yet known. This defect often occurs along with other congenital heart defects.

In adults, ventricular septal defects are a rare but serious complication of heart attacks. These holes are related to heart attacks and do not result from a birth defect.

Patients with ventricular septal defects may not have symptoms.

The most common symptoms, however, include:

• Shortness of breath
• Fast breathing
• Hard breathing
• Paleness
• Failure to gain weight
• Fast heart rate
• Pounding heart
• Sweating while feeding
• Frequent respiratory infections

Listening with a stethoscope usually reveals a heart murmur (the sound of the blood crossing the hole). The loudness of the murmur is related to the size of the defect and amount of blood crossing the defect.

Tests may include:

• Chest x-ray -- looks to see if there is a large heart with fluid in the lungs
• ECG -- shows signs of an enlarged left ventricle
• Echocardiogram -- used to make a definite diagnosis
• Cardiac catheterization (rarely needed, unless there are concerns of high blood pressure in the lungs, in which case surgery to close the defect is generally not recommended)
• MRI of the heart -- used to find out how much blood is getting to the lungs

Many small defects will close on their own. For those defects that do not spontaneously close, the outcome is good with surgical repair. Complications may result if a large defect is not treated.

• Heart failure
• Infective endocarditis (bacterial infection of the heart)
• Aortic insufficiency (leaking of the valve that separates the left ventricle from the aorta)
• Damage to the electrical conduction system of the heart during surgery (causing arrhythmias)
• Delayed growth and development (failure to thrive in infancy)
• Pulmonary hypertension (high blood pressure in the lungs) leading to failure of the right side of the heart

Most often, this condition is diagnosed during routine examination of an infant. Call your infant's health care provider if the baby seems to be having difficulty breathing, or if the baby seems to have an unusual number of respiratory infections.

Except for the case of heart attack associated VSD, this condition is always present at birth.

Drinking alcohol and using the antiseizure medicines depakote and dilantin during pregnancy have been associated with increased incidence of VSDs. Other than avoiding these two things during pregnancy, there is no known way to prevent a VSD.

Zipes DP, Libby P, Bonow RO, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 8th ed. St. Louis, Mo; WB Saunders; 2007.