Continuous extra flow towards lungs causes stiffness of minute blood vessels inside the lungs which causes reverse flow from lungs to the heart. This is dangerous. This is called Eisenmenger syndrome. At this stage we cannot close the hole anyway.
Atrial Septal Defect (ASD)
If a hole is present at the separating membrane of the upper chambers of the heart, it is called atrial septal defect (ASD). ASDs are three types according to the sizes of the hole. Small, medium and large sized. Most of the ASDs are asymptomatic and may remain undiagnosed until later in life. They may come to medical attention due to incidental findings of abnormal heart sound while checked by doctors. Very rarely they may present with recurrent respiratory tract infections and failure to thrive.
Older children may present with symptoms of mild fatigue and dyspnoea that may worsen with age. They may have irregular heartbeat or arrhythmia. Sometimes, ASD of a female person can be diagnosed during pregnancy when the pulmonary pressure becomes higher and can have respiratory distress. If ASD is diagnosed in time we can close the hole with device without any surgery if ASD rims are sufficient. If rims are not sufficient, surgery is required.
Ventricular Septal Defect (VSD)
Hole present at the separating membrane between lower two chambers of the heart is called ventricular septal defect (VSD). VSDs are of various types according to sizes (small, medium and large) and sites (central/perimembranous, inlet, muscular and outlet/subpulmonic).
The typical presentation of a large VSD occurs at approximately 4-8 weeks of age. In some cases, a preceding respiratory infection can blur the picture and lead to mis-diagnosis. As a result of drop in pulmonary vascular resistance over the first few weeks of life, the infant with a large VSD will develop symptoms of congestive heart failure. In case of moderate sized VSD the babies have frequent attack of lower respiratory tract infection with sleep and suck cycle (after taking small feed, becoming tired, go to sleep and again sleep) are common symptoms. If untreated the VSD gradually increase the pulmonary/lung pressure.
Patent Ductus Arteriosus (PDA)
This is an unusual connection between the great artery from heart to whole body and great artery to lungs from heart. Types of PDA are small, moderate and large size. The same symptoms of VSD are present in case of PDA.
We can close the holes by two ways. One is by device closure which depends upon the size and site of the shunt. Device closure does not require open heart surgery hence baby does not have any scar mark. Baby needs to stay in the hospital only one to two days for that procedure.
The other method is open heart surgery. Both of these procedures have been performed in our country. These congenital heart diseases can be prevented by giving MMR vaccine to the mother before being pregnant.
The writer is a Consultant Paediatric Cardiologist at the Apollo Hospitals, Dhaka, Bangladesh.