Congenital Heart Diseases (CHD) are defined as the structural, functional or positional abnormality of the heart, in isolation or in combination present from birth, but may manifest any time after birth or may not manifest at all. Some of these may be discovered later. These are primarily seen in newborn, and children; although in our country it is not uncommon to see adults with uncorrected CHD. The burden of congenital heart disease in India is likely to be enormous, due to a very high birth rate. This heavy burden emphasizes the importance of this group of heart diseases. The reported incidence of CHD is 8-10/1000 live births according to various series from different parts of the world.
Nearly one third to half of these CHDs are critical, requiring intervention in the first year of life itself. Rapid advances have taken place in the diagnosis and treatment of CHD over the last 6 decades. There are diagnostic tools available today by which an accurate diagnosis of CHD can be made even before birth. With currently available treatment modalities, over 75% of infants born with critical heart disease can survive beyond the first year of life and many can lead near normal lives thereafter.
Congenital Heart Disease is considered to be of multifactorial origin – an effect of interaction between a genetic predisposition and an environmental influence. Maternal diseases like Gestational Diabetes, Rubella, Mumps, Connective tissue disorders, maternal drug intake and family history may contribute. The disease pattern can have a major implications in antenatal management, screening, adolescent vaccination, contraception, family planning and genetic counseling, in addition to health planning.
Congenital heart diseases can be broadly classified into
- Acyanotic Congenital Heart Disease (ACHD)
- Cyanotic Congenital Heart Disease (CCHD)
Acyanotic congenital heart diseases can be broadly classified into Shunt lesion – where blood from the left side of heart is shunted to right side, and Obstructive lesion – where there is an obstruction to the flow of blood. In Cyanotic congenital heart disease, the defects in the heart results in the shunting of blood from right side of heart to the left. This results in the mixing up of blood with decreased oxygen content from the right side of heart with that of the right side, resulting in bluish discoloration of skin, referred to as cyanosis.
The important ones in the above classification are:
Acyanotic Congenital Heart Disease
Atrial septal defect
Ventricular septal defect
Patent ductus arteriosus
Coarctation of aorta
Cyanotic congenital heart disease
Tetrology of Fallot
Transposition of great arteries
There are many more diseases among the congenital heart disease such as tricuspid Atresia, double outlet right ventricle(DORV), Total anomalous pulmonary venous connection (TAPVC), hypoplastic left heart syndrome and many more. All these conditions can occur in isolation or in combination.
Symptoms and signs are related to the type and severity of the heart defect. Some children have no signs while others may exhibit shortness of breath, cyanosis – bluish discoloration of skin, chest pain, syncope – loss of consciousness , sweating, heart murmur – sound heard due to turbulent blood flow through the defects, respiratory infections, poor feeding, or poor growth, build up of blood and fluid in lungs, feet, ankles and legs. However, all heart murmurs are not caused by congenital heart defects. CHD symptoms frequently present early in life, but it’s possible for some CHDs to go undetected throughout life.
Management of the CHD depends on the type and severity of the condition. Small Acyanotic CHDs such as Atrial septal defects may remain asymptomatic throughout life. Others may manifest early in life and have to be treated aggressively with surgical options. Small defects need supportive measures to prevent heart going into failure.
Medications include diuretics, which eliminates water from the body and thereby decrease the work load of heart, digoxin, which function by decreasing the oxygen demand of the heart. Any recurrent infection has to be treated promptly. Some defects require surgical procedures to repair as much as possible to restore circulation back to normal. In some cases, multiple surgeries are needed to be performed to help balance the circulation. Interventional cardiology now offers patients minimally invasive alternatives to surgery.