Congenital heart defect (CHD), also known as a congenital heart anomaly or congenital heart disease, is a problem in the structure of the heart that is present at birth. It represents a group of heart defects that cause serious, life-threatening symptoms and requires intervention within the first days or first year of life. CCHD is often treatable if detected early.
Some babies affected with CCHD can look and act healthy at first, but within hours or days after birth, they can have serious complications. If early detection is done, infants affected with CCHD can often be treated and lead longer healthier lives.
Sign and symptoms of Congenital Heart Disease
Digital clubbing with cyanotic nail beds in an adult with tetralogy of Fallot. Sign and symptoms are related to type and severity of the heart defect. Some symptoms frequently present early in life, but it is possible for CHD to go undetected throughout life. Some children have no signs while others may exhibit shortness of breath, cyanosis, fainting, heart murmur, under-development of limbs and muscles, poor feeding or growth, or respiratory infection. Congenital heart defects because abnormal heart structure resulting in a production of certain sounds called heart murmur. Not all heart murmurs are caused by congenital heart defects though it can be detected from auscultation.
Congenital heart defects are associated with an increased incidence of some other symptoms, together with being called the VACTERL association.
V- Vertebral anomalies
A- Anal atresia
C- Cardiovascular anomalies
T- Tracheoesophageal fistula
E- Esophageal Atresia
R- Renal (Kidney) and/or radial anomalies
L- Limb defects
- The patient assuming a crouching position
- Cyanosis: facial discolouration (particularly the lips) and digit discolouration (fingers & toes)
- A history of inadequate feeding
- Unusually large toe and fingernails
- Delayed development( both biological and psychological)
Ventricular septal defect (VSD), atrial septal defects, and tetralogy of Fallot are the most common congenital heart defects seen in the VACTERL association. Less common defects in the association are truncus arteriosus and transposition of the great arteries.
Classification of Congenital Heart Disease
A number of classification systems exist for congenital heart defects.
Hypoplastic left heart syndrome and hyperplastic right heart syndrome
Hypoplasia can affect the heart, typically resulting in the underdevelopment of the right ventricle of the left ventricle, which leads only one side of the heart to be the capability of pumping blood to the body and lungs effectively It is a rare condition but is the most serious form of CHD. It is called hypoplastic left heart syndrome when if, affects the left side of the heart and hypoplastic right heart syndrome when it affects the right side of the heart. In both conditions, the presence of the patent ductus arteriosus (and, when hypoplasia affects the right side of the heart, a patent foramen ovale) is vital to the infant’s ability to survive until emergency heart surgery can be performed, since without these pathways blood cannot circulate to the body (or lungs, depending on which side of the heart is defective).
- Obstruction defects
- Ventricular outflow tract obstruction: obstruction defects occur when heart valves, arteries or veins are abnormally narrow or blocked. Any narrowing or blockage can cause heart enlargement or hypertension
- Septal defects: the septum is a wall of tissue which separates the left heart from the right heart. Defects in the interatrial septum or the intraventricular septum allow blood to flow from the right side of the heart to the left, reducing the heart’s efficiency. Ventricular septal defects are collectively the most common type of CHD, although approximately 30% of adults have a type of atrial septal defect called probe foramen ovale.
- Cyanotic defects: cyanotic defects are called such because they result in cyanosis, a bluish-grey discolouration of the skin due to lack of oxygen in the body. Such defects include persistent truncus arteriosus, total anomalous pulmonary venous connection, tetralogy of Fallot, transposition of the great vessels and tricuspid atresia.
- Aortic stenosis
- Atrial septal defect
- Atrioventricular septal defect
- Bicuspid aortic valve
- Double inlet left ventricle
- Double outlet right ventricle
- Pulmonary stenosis
- Pulmonary atresia
- Transposition of great vessels
Causes of Congenital Heart Disease
The cause of congenital heart disease may be either genetic or environmental, but is usually a combination of both
- Genetic: most of the known causes of congenital heart disease are sporadic genetic changes, either focal mutations or deletions or addition of segments of DNA. Large chromosomal abnormalities such as trisomy 21, 13 and 18 cause about 5-8% of cases of CHD, with trisomy 21 being the most common genetic cause. Small chromosomal abnormalities also frequently lead to congenital heart disease.
- Environmental: known environmental factors include certain infections during pregnancy such as Rubella drugs, alcohol, hydantoin, lithium and thalidomide) and maternal illness ( diabetes mellitus, phenylketonuria, and systemic lupus erythematosus)
- Family history of congenital heart disease
- Pregnancy-induced hypertension
- Smoking drinking during pregnancy
- Premature birth or delivery
- Maternal infection
Many congenital heart defects can be diagnosed prenatally by fetal echocardiography. This test which can be done during the second trimester of pregnancy.
If baby is born with cyanotic heart disease, the diagnosis is usually made shortly after birth due to the blue colour of their skin
If a baby is born with a septal defect or an obstruction defect, often their symptoms are only noticeable after several months or sometimes even after many years.
Sometimes CHD improves without treatment. Other defects are so small that they don’t require any treatment. It is a serious condition that requires medications and/or surgery most of the time. Medication includes diuretics, which aid the body in eliminating water, salts and digoxin for strengthening the contraction of the heart. This helps to slow down the heartbeat and also removes the fluid from the tissues. Some of the defects require surgical procedures to restore circulation back to normal. In some cases, multiple surgeries are needed.
Transcatheter pulmonary valve technology provides a less-invasive means to extend the life of a failed RVOT conduct and is designed to allow physicians to deliver a replacement pulmonary valve via catheter through the patient’s blood vessels.
- Prophylactic treatment
- Prostaglandin E to keep ductus arteriosus patent
- Surgery: Glenn Shunt, Hemi-Fontan procedure, Fontan procedure. The purpose of the operations is to redirect the blood flow of the deoxygenated blood to the lungs by attaching the superior vena cava directly to the pulmonary artery causing the blood that flows into the lungs to be oxygenated before entering the chambers on the right side of the heart.
The outlook for children with congenital heart defects varies greatly depending on the specific defect, children who receive early diagnosis and appropriate medical attention usually have the best possible prognosis.
It is important that the children diagnosed with heart defects need to have a regular monitoring throughout their lives to prevent the other complications. It is undetectable in childhood can cause disabilities as the person ages so, it’s important for everyone to have yearly checkups throughout childhood, adolescence and into adulthood.
The exact cause of the most congenital heart defects is unknown, it may not be possible to prevent these conditions. However, there are some ways to prevent the risk of having congenital heart disease:
- Get rubella (German measles) vaccine: a rubella infection during pregnancy may affect the baby’s heart development. Try to avoid during pregnancy or get vaccinated before conceiving.
- Control chronic medical conditions: the diabetic mother should keep monitoring their blood pressure level to reduce the risk of heart defects.
- Avoid harmful substances: during pregnancy, avoid the strong and smelling substances, don’t take any drugs, dietary supplements, smoking or drinking.
- Take a multivitamin with folic acid: daily consumption of 400 micrograms of folic acid has been shown to reduce the birth defects in the brain, spinal cord and heart as well.