Definition

The heart is divided into four chambers that help circulate blood through the body. The top two chambers are called atria. The bottom two chambers are called ventricles. Two valves are between the upper and lower chambers. Tissue called the septum divides the chambers. The tissue grows as the fetus develops.

An atrioventricular septal defect is present at birth. It occurs when any of the tissues that divide the septum do not grow completely. This leaves one or more "holes." It may also leave one leaky valve instead of two separate valves.

The heart may have to work harder to circulate blood correctly. Open-heart surgery is often needed to correct the defect in babies.

Causes

The septal tissue fails to grow correctly as the fetus develops in the womb. This results in atrioventricular septal defect.

Ventricular Septal Defect Copyright © Nucleus Medical Media, Inc.

Risk Factors    TOP

Risk factors that increase the chance that a baby will be born with a ventricular septal defect include:

• A family history of heart defects
• Down syndrome —Nearly one in five babies with Down syndrome will have this heart defect
• Alcohol consumption or drug abuse by the mother during pregnancy
• A mother with diabetes
• Rubella infection during the first three months of pregnancy
• Exposure to thalidomide, anticonvulsant medications, or lithium salts while in the womb
• Exposure to certain industrial chemicals during pregnancy

Symptoms    TOP

Symptoms include:

• Difficulty feeding, such as sweating or shortness of breath while eating
• Failing to gain weight
• Lung congestion
• A bluish tint to lips and fingernails, called cyanosis

Diagnosis    TOP

Your doctor will ask about your baby's symptoms and medical history. A physical exam will be done.

• Your doctor may need pictures of your baby's heart. This can be done with a Chest x-ray.
• Your doctor may need information about how your baby's heart functions. This can be done with:
  • Echocardiogram
  • Electrocardiogram (ECG, EKG)

Treatment    TOP

A doctor may recommend any of the following treatments for your baby:

• Medicines to strengthen the heart, keep the heartbeat regular, or decrease the amount of fluid in circulation
• A pacemaker to regulate the heart
• A high calorie diet and/or breastfeeding to manage poor weight gain
• Ongoing observation of the symptoms and the defect
• Limited physical activity depending on the severity of the defect
• Counseling to help you adjust to your baby's diagnosis and treatment
• Surgery in early childhood to close the hole (recommended when the defect is severe)
• Diuretics and digoxin to treat heart failure
• Antibiotics before and after surgery to reduce the risk of bacterial infections

Prevention    TOP

It may not be possible to prevent the condition because the exact cause is unknown. A septal defect can be identified, watched, and treated early in pregnancy and childhood:

• If you are pregnant or planning to become pregnant, seek early and regular prenatal care, get exercise, and eat a well-balanced diet.
• Control your blood sugar levels if you have diabetes.
• Avoid drugs, cigarettes, and alcohol.
• A prenatal ultrasound when the fetus is 10-14 weeks old will identify many babies with heart defects.
• If you have a child with this defect, consult a genetics counselor to find out if your future children are also at risk.

12 Week Fetus Copyright © Nucleus Medical Media, Inc.