What is a ventricular septal defect?

 A ventricular septal defect (VSD) is a hole in the wall (septum) that separates the heart’s two lower chambers (ventricles). Ventricular septal defects usually occur by themselves, without other birth defects of any kind. Experts estimate that VSDs account for about 30 percent of all congenital heart defects, occurring in 1 out of every 500 babies.

What are the symptoms of VSD?

The symptoms and treatment for VSD depend on the size of the hole and where it is located. The size of the defect determines its effects on the heart’s function. When the opening between the ventricles is large, oxygen-containing blood flows backwards into the right ventricle instead of out into the body. From the right ventricle, this oxygen-containing blood gets pumped back to the lungs, displacing blood in the lung circulation that needs oxygen. This inefficient blood flow causes the heart to pump harder, trying to compensate.

As a result, the heart may enlarge and high blood pressure may develop in the arteries of the lungs (pulmonary hypertension). A person with a large VSD may experience shortness of breath, fatigue and weakness.

How is VSD diagnosed?

Ventricular septal defects frequently are diagnosed at birth or within a few days from birth because the doctor can hear the distinctive murmur. Older children or adults with an undetected VSD may experience shortness of breath with exercise or heart rhythm problems that send them to a doctor. Diagnosis may include:

• Chest x-ray

• Electrocardiogram to evaluate the heart’s electrical system

• Transthoracic Echocardiogram with Doppler imaging: Ultrasound images are obtained to show the size and function of the heart’s chambers, assess the condition of the heart valves and measure the velocity of blood flow across the VSD

• Coronary angiography in patients at risk of coronary artery disease or in patients over age 40 if a surgical repair is planned.

• MRI to detect other associated cardiac abnormalities

Does VSD always require treatment?

Approximately 75 percent of small VSDs close on their own within the first year of life or by age 10 and do not require any treatment other than careful monitoring. For medium to large VSDs, the spontaneous closure rate is about 5 to 10 percent. If a VSD has not closed by age 10, spontaneous closure probably will generally not occur; it is rare for a VSD in an adult to close on its own.

An adult who has a VSD without any symptoms probably does not require intervention but should have regular checkups by a physician who specializes in adult congenital heart disease. Although the VSD may not be causing heart or lung problems or symptoms, adults with unrepaired VSDs still have a higher than normal risk for heart valve problems and endocarditis, a potentially life-threatening infection of the heart.

Pregnancy and VSD

Women with repaired VSDs and normal heart function, or those with small, asymptomatic VSDs can have children without a higher than normal risk for problems during pregnancy. Women who have an unrepaired VSD or a closed VSD with heart and/or lung complications who desire to become pregnant should seek the advice of an adult congenital heart disease specialist and a specialist in high-risk pregnancy. With proper prenatal care and monitoring, these women usually can have successful pregnancies also.

Pregnancy is not recommended for women with large VSDs and pulmonary hypertension because of high maternal mortality rates. When either the man or women has a congenital heart defect of any kind, their infant has a higher than normal risk of also having a congenital heart defect.

Eisenmenger Syndrome

About 10 percent of people with VSD develop Eisenmenger Syndrome, a complex array of problems caused by the difference in pressure between the left and right ventricles. Early on, blood flows backwards through the large opening in the septum and into the right ventricle and floods the pulmonary arteries. Over time, changes occur in the thickness and elasticity of the pulmonary artery walls and high blood pressure (pulmonary hypertension) occurs in those vessels. As the blood vessels lose their elasticity, the heart pumps harder, causing it to weaken and results in right-sided heart failure. Flow then reverses across the VSD, resulting in low oxygen blood flowing into the systemic circulation. This can result in cyanosis (low blood oxygen, often seen as blue lips and extremities) and several other complications. These individuals also may develop atrial fibrillation (a rhythm disturbance of the upper heart chambers), aneurysms in the pulmonary arteries and other complications. The average life expectancy of people with Eisenmenger Syndrome is less than 40 years. Newer medical therapies and close medical attention may significantly improve outcomes in these patients.