VENTRICULAR SEPTAL DEFECT
 

What is a VSD?
 

This condition describes a hole between the two lower or pumping chambers of the heart. Blood flows through this hole and creates a sort of short circuit of flow to the lungs. Normally, blood coming to the left sided chambers that is rich in oxygen is pumped to the whole body before it returns with less oxygen to the right sided chambers, and gets pumped to the lungs. With an VSD, some amount of blood (depending on the size of the hole) goes across the hole to cause extra flow to the lungs leading to rapid return to the left sided chambers and they increase in size (enlargement). As the pressure in the left pumping chamber is high, the flow across the VSD is often quite turbulent and causes a loud murmur. Sometimes, when the hole is large with high pressures being transmitted to the right sided chambers, paradoxically the murmur may be soft.
 

 

Why does it occur?
 

We don’t quite know why these holes occur. There is certainly a genetic basis to VSD but we haven’t identified a single genetic defect that explains its occurrence consistently. VSD is one of the most common heart defects but it is also occurs in association with complex congenital heart diseases.
 

 

What are the signs?

 

Small VSDs are often picked up during routine check-up or during other illness. Babies or children are referred for a heart murmur. They are generally quite well and those located in the muscle part of the wall (septum) called muscular VSD are most likely to close by themselves. Medium to large defects often cause excessive flow to the lungs and babies can present with heart failure. They breathe fast, struggle with feeding, and consequently struggle to gain weight. They could have recurrent chest infections needing antibiotics. Some large defects cause babies to be sick within the first few weeks of life with very high flow and pressure in the lung circulation and need urgent treatment. The advent of fetal echocardiography has helped many of these defects to be identified earlier resulting in quicker management.
 

 

How is it diagnosed?
 

The diagnosis of VSD can be made from a history, clinical examination and often complemented by a chest X ray. A definitive diagnosis is only made by echocardiography which is a gold standard investigation for ventricular septal defects. In babies and infants, echocardiogram is often the most important test to determine the diagnosis and severity of VSD and can provide enough information even to proceed to surgery.

 

 

How is it treated ?
 

Small defects often need no treatment but infrequent follow-up. Rarely, even when some small VSDs need treatment if they are located close to outlet valves causing the valve to leak. Most medium sized holes and all large holes need treatment by surgery. Dr Khambadkone works closely with renowned cardiac surgeons. The aim of surgery is usually to repair the heart by closing the hole with a patch.  The surgeons use heart lung bypass to safely work on the heart and preserve organ function. Some VSDs can be treated by device closure using small plugs made of wire mesh woven into shape delivered through a vein in the neck under general anaesthesia. The plug then blocks flow by forming a clot within it. Dr Khambadkone is an expert in identifying the defects that are suitable for device closure and performs these procedures. Medications are used in those who have symptoms of heart failure. In young infants, tube feeding of high caloric formula may be necessary to help gain weight.