Congenital heart defects are structural abnormalities in the heart that are present from birth. They affect about 1% of live births. The most common defects involve communication between the left and right sides of the heart or a ‘hole in the heart’ which allows the mixing of arterial or oxygenated blood with venous or deoxygenated blood. The most common is the ventricular septal defect (VSD) with communication between the left and right ventricles. Other types are atrial septal defect (ASD) and patent foramen ovale (PFO) which both lead to a communication between the left and right atria. While an ASD arises due to an anatomical defect, a PFO is a normal variant that is usually asymptomatic.
There are genetic and developmental abnormalities noted to be underlying the incidence of heart defects. A family history increases the risk of these defects in children.
This is the second most common congenital heart defect, after the bicuspid aortic valve. There is a hole or defect present in the septum dividing the left and right ventricles of the heart. A VSD may be associated with other heart defects or maybe the only lesion. Some VSDs may be very small and close spontaneously in childhood whereas others may be very large and present early in life with rapid progression of symptoms.
There are three types of ASDs which vary depending on the site on the septum between the left and right atria and the mechanism of formation
Prior to birth, there exists communication between the left and right atria known as the foramen Ovale. This is guarded by a flap and is necessary for normal circulation in the fetus. After birth, it closes spontaneously. Failure to close completely leads to PFO. A PFO is considered to be a normal variant and does not cause any symptoms.
It is important to note, however, that a PFO can allow a clot forming in the body, to move from the right to the left side of the heart and reach the brain to cause a stroke.
As these conditions are generally asymptomatic in the early stages, the diagnosis is usually suspected when an abnormal heart sound or a murmur is heard during a routine physical exam. Family history aids in making the diagnosis. The following are additional tests used to confirm the diagnosis:
Not all defects require treatment. Minor defects can be monitored using Echo. Treatment when indicated, with surgery or minimally invasive procedures is beneficial in preventing complications. Once complications set in and the vessels in the lungs are affected, there is no definitive treatment. The general treatment options include:
The overall prognosis in individuals with septal defects is good in minor cases and in those who undergo corrective procedures. Severe defects when untreated can lead to complications and death.