Causes

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 one of the most common congenital heart defects. 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.

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 do not result from a birth defect.

Symptoms

Patients with ventricular septal defects may not have symptoms. However, if the hole is large, the baby often has symptoms related to heart failure.

The most common symptoms include:

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

Exams and Tests

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:

• Cardiac catheterization (rarely needed, unless there are concerns of high blood pressure in the lungs)
• 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
• MRI of the heart -- used to find out how much blood is getting to the lungs

Treatment

If the defect is small, no treatment is usually needed. However, the baby should be closely monitored by a health care provider to make sure that the hole eventually closes properly and signs of heart failure do not occur.

Babies with a large VSD who have symptoms related to heart failure may need medicine to control the symptoms and surgery to close the hole. Medications may include digitalis (digoxin) and diuretics.

If symptoms continue even with medication, surgery to close the defect with a Gore-tex patch is needed. Some VSDs can be closed with a special device during a cardiac catheterization, although this is rarely done.

Having surgery for a VSD with no symptoms is controversial. Discuss this carefully with your health care provider.

Outlook (Prognosis)

Many small defects will close on their own. Surgery can repair defects that do not close. Complications may occur if a large defect is not treated.

Possible Complications

• 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 an irregular heart rhythm)
• Delayed growth and development (failure to thrive in infancy)
• Heart failure
• Infective endocarditis (bacterial infection of the heart)  
• Pulmonary hypertension (high blood pressure in the lungs) leading to failure of the right side of the heart

When to Contact a Medical Professional

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.

Prevention

Except for VSD that is caused by a heart attack, this condition is always present at birth.

Drinking alcohol and using the antiseizure medicines depakote and dilantin during pregnancy may increase the risk of VSDs. Other than avoiding these things during pregnancy, there is no known way to prevent a VSD.

Alternative Names

VSD; Interventricular septal defect

References

Webb GD, Smallhorn JF, Therrien J, Redington AN. Congenital heart disease. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 65.

Updated: 4/1/2012

Reviewed by: Kurt R. Schumacher, MD, Pediatric Cardiology, University of Michigan Congenital Heart Center, Ann Arbor, MI. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.