The ventricular septal defect is a congenital heart condition in which there is one or more holes in the interventricular septum, which the muscular wall separating the right ventricle from the left. Faults with NKX2.5 gene can cause ventricular septal defect. In the early stages of fetal development the right and left ventricles of the heart are not separated, but as the fetus develops a wall forms to separate these two lower chambers of the heart; but sometimes this muscular wall does not completely form and, as a result, a hole remains, which is known as a ventricular septal defect (VSD).
A ventricular septal defect can be detected by cardiac auscultation. Classically, a VSD causes a pathognomonic holo- or pansystolic murmur. Auscultation is generally considered sufficient for detecting a significant VSD. The murmur depends on the abnormal flow of blood from the left ventricle, through the VSD, to the right ventricle. If there is not much difference in pressure between the left and right ventricles, then the flow of blood through the VSD will not be very great and the VSD may be silent. Confirmation of cardiac auscultation can be obtained by non-invasive cardiac ultrasound. VSD is an acyanotic congenital heart defect, with a left-to-right shunt, so there are no signs of cyanosis. Ventricular septal defect is usually symptomless at birth and usually manifests a few weeks after birth.
Most cases of ventricular septal defect do not need treatment as the abnormal holes close and heal during the first years of life. Treatment is either conservative or surgical. Smaller congenital VSDs often close on their own, as the heart grows, and in such cases may be treated conservatively. Some cases may necessitate surgical intervention.