Ventricular Septal Defect
Ventricular Septal Defect Overview continued...
The ventricular septal defect may not be heard with a stethoscope until several days after birth. This is because a newborn's circulatory system changes during the first week, with a drop in the lung or pulmonary pressure creating the greater pressure differential between the 2 ventricles, with may increase the left-to-right shunt and produce an audible murmur.
Ventricular septal defects are the most common congenital heart defects in infants
- The condition occurs in about 25% of all infants born with a heart defect.
- These defects are more common in premature infants.
Ventricular Septal Defect Causes
No one knows what causes ventricular septal defects, but they probably come from a malformation of the heart that occurs while the infant is developing in the womb.
- There may be just one hole or several holes in the septum.
- The septum itself is divided into multiple areas, including the membranous part, the muscular part, and other areas called the inlet and outlet. Any or all of these parts can have a hole.
- The location of the hole depends on where the malformation takes place during fetal development.
The most common type of ventricular septal defect is the membranous variant. In this type, the hole is located below the aortic valve, which controls flow of blood from the left ventricle into the main artery of the body, the aorta.
Ventricular Septal Defect Symptoms
Small holes in the ventricular septum usually produce no symptoms but are often recognized by the child's health care provider when a loud heart murmur along the left side of the lower breast bone or sternum is heard. Large holes typically produce symptoms 1-6 months after an infant’s birth. The left ventricle begins to fail, producing the following symptoms:
- Fast breathing
- Very fast heartbeats
- Decreased feeding
- Poor weight gain
When a ventricular septal defect is not detected early in life, it can cause more severe problems and more severe symptoms as time goes on. The biggest concern is development of high pressure in the lungs (pulmonary hypertension). If the ventricular septal defect is not surgically closed, irreversible pulmonary hypertension can develop, and the child may no longer benefit from surgery. The following are typical symptoms of pulmonary hypertension:
- Shortness of breath
- Chest pain
- Bluish discoloration of the skin (cyanosis)
The skin turns faintly bluish when the tissues are not receiving quite enough oxygen. This condition is often termed "hypoxemia" or "hypoxia."