Understanding Congenital Heart Disease
Congenital Heart Disease is a defect in the structure of the heart that is present since birth. The incidence of Congenital Heart Disease is 6-8 per 1000 live born children. Congenital Heart Diseases includes Cyanotic (the baby looks blue) and Acyanotic Heart Defects (baby appears pink). The few common Acyanotic Congenital Heart Diseases are Ventricular Septal Defect (VSD), Atrial Septal Defect (ASD) and Patent Ductus Arteriosus (PDA). The most common cyanotic congenital heart disease is Tetralogy of Fallot.
Some heart diseases which do not present in early infancy, but present at a later age are known as Acquired Heart Diseases.
Ventricular Septal Defect (VSD)
What is a VSD? How does it affect the heart?
This is the most common congenital heart defect. In simple words it is a hole in the wall separating the two lower chambers of the heart.
Normally, the left side of the heart (Left Ventricle) pumps oxygenated (pure) blood to the body and the right side (Right Ventricle) pumps deoxygenated (or impure) blood to the lungs for oxygenation. There is no mixing of the pure and impure blood in a normal heart. In a child with VSD, blood travels across the hole from the left ventricle to the right ventricle and out into the lung arteries. In babies with large VSDs, because of the hole in the heart, the baby will develop increased blood flow to lungs and it leads to increased pressure in the lung’s blood vessels called as Pulmonary Arterial Hypertension (PAH), which means the pressure in the arteries of the lung increases much more than normal. If the VSD is not closed/intervened timely, the PAH may become irreversible and cause permanent damage to the lung arteries.
How does it occur?
During the embryological development of the baby in the mother’s womb, a wall forms between the lower chambers of the heart, dividing it into left and right chambers. Failure in the formation of the wall/septum, leads to a VSD. In most children, the exact cause is still not known. Some children can have other heart defects along with a VSD. In the majority of patients, congenital heart defects occur without any hereditary or genetic causes, although some patients with genetic syndromes, such as Down Syndrome, are known to have specific congenital heart defects.
What are the symptoms?
If the hole is small, the baby can be asymptomatic and is usually diagnosed on evaluation of a murmur (extra sound in the heart heard with stethoscope) detected incidentally by the doctor during a routine check-up.
If the hole is large, the child can present with
- feeding difficulty,
- fast breathing,
- repeated respiratory tract infections
- failure to gain weight
Some small VSDs can close spontaneously but moderate or large sized VSDs will need treatment, either by surgical or interventional procedure.
What are the available treatment options?
In cases of large VSDs, medications can be used temporarily for relief of symptoms but medications DO NOT and CANNOT close the defect nor can medications prevent damage caused by pulmonary hypertension.
However, there is still a myth among the general people that a hole in the heart can be closed with medication. But there is no drug that will close a hole in the heart. If a small hole has to close, it will close naturally, and not with medications. No large VSD will close or get smaller naturally or with medications, and if surgery is not done in a timely manner, permanent damage can occur.
The child will need surgical closure of a large VSD within 3-6 months of age and failure to do so may result in poor growth, developmental delay and even permanent damage to the lung arteries. Medium sized VSDs can also be closed surgically.
Trans-catheter Device Closure:
Medium sized VSDs can also be closed with a device in the cath-lab, without the need of an open-heart surgeries.
If the VSD is small, the child will grow normally and the VSD may close spontaneously but you need to follow-up with your cardiologist at regular intervals.
In general, once a VSD is diagnosed or suspected, a complete evaluation by a paediatric cardiologist is essential to get a detailed diagnosis and a treatment plan. The paediatric cardiologist will also advise you whether, and when, a surgical/interventional treatment is indicated.
Surgical closure of VSD is an open-heart surgery where the child is under general anaesthesia and put on Cardiopulmonary bypass (a heart lung machine). The VSD is closed with a patch. The average duration of hospital stay is 7-10 days.
If an infant is very ill, or has multiple VSDs or a very large VSD, a temporary surgery can be performed to relieve symptoms and high pressure in the lung arteries. This surgery, known as PA banding, helps to reduce the blood flow to the lungs and to a certain extent prevents damage to the lung arteries. Later when the child grows a little older, another surgery is done to remove the PA band and close the VSD with open-heart surgery.
Depending on the size and location of the VSD, some small and medium sized defects can be closed in the cardiac catheterisation lab with a minimally invasive technique. A sheath is inserted from the leg vein and through this sheath, a device is deployed at the site of the VSD, causing complete occlusion of the defect. The average time to complete the procedure is 1-2 hours. The procedure can be done under local anaesthesia or minimal sedation. The duration of hospital stay is 2 days. After the procedure, the child is advised to continue anti platelet drugs (Aspirin) for a period of 6 months.
Nowadays, with modern scientific equipment and techniques, VSD closure, either surgically or with trans-catheter intervention is an extremely safe procedure with very high success rates.
Periodic follow up with the cardiologist and cardiac surgeon is essential after cardiac surgery. Usually no long term medication is needed post-surgery. The long term outcome is excellent with normal life expectancy if the VSD is treated timely.
It is an infection of the heart’s inner lining and valve. Any child who has a heart disease is prone to have Endocarditis.
It is advisable to maintain good dental hygiene in general and particularly in children with corrected/uncorrected congenital heart disease. After surgery it is advisable to take Endocarditis Prophylaxis for the initial few months post-surgery for dental procedures.
For most congenital heart defects, including VSD, routine periodic cardiac follow-up is advised, whether or not the defect is operated.
The long-term outlook is excellent, and usually no medicines and no additional surgery or catheterization are needed.