Congenital Heart Disease also known as Congenital Heart Defect (CHD) is a structural defect in the heart &/or the vessels associated to it, present at birth.
CHD is mainly of two types:
- Cyanotic Heart defect: Occurs due to the mixture of deoxygenated & oxygenated blood entering the systemic circulation.
- Non-cyanotic Heart defect: In this defect the blood flows from the left side of the heart to the right side of the heart, due to structural defect.
Further classification of CHD can be made as:
- Hypoplasia: Underdevelopment of the right ventricle or the left ventricle, which can lead to only one side of the heart to be able to pump blood effectively to the body & lungs effectively.
- Obstructive defects: Occurs when the heart valves, arteries or veins are abnormally narrow or blocked. This can lead to hypertension & enlargement of the heart. Eg, narrowing of the aorta, pulmonary artery, bicuspid valve.
- Septal defects: The septum is a tissue which separates the left side of the heart from the right side. Defects in the interatrial septum or the interventral septum can lead to the flow of the blood from the left side to the right side which causes inefficiency of the heart.
- Cyanotic defects: Result in a bluish-grey discoloration of the skin due to lack of oxygen.
SIGNS & SYMPTOMS OF CHD
- Shortness of breath
- Bluish discoloration of the skin
- Crying & irritability
- A fast heart rate
- Poor feeding
- Under development of limbs & muscles
- Respiratory infections
- Large toe & fingernails
- Congested cough
- Heart murmur.
- Malformation of the spine
- Malformation of the rectum
- Fistula between the esophagus & the trachea
- Structural deformity in which the esophagus is not normally connected to the stomach, and instead ends as a pouch like formation.
- Abnormality of the kidneys
- Defects in the formation of limbs
- High blood pressure in the arteries supplying blood to the lungs.
- Problems in heart rhythm
- Formation of clots in the heart
- Infection & inflammation of the lining of the heart (Endocarditis).
- High fever
- Heart Failure
- Problems in memory
- Problems in growth.
CAUSES & RISK FACTORS
- Genetic factors like:
a) Abnormal number of chromosomes (Turner’s Syndrome & Down’s Syndrome)
b) Repetition in certain sections of a genome (Burnside-Butler Syndrome, DiGeorge Syndrome)
c) Abnormal insertion, deletion & substitution of nucleotide bases in a genome (Holt-Oram Syndrome, Noonan Syndrome)
d) Mutation in the protein coding of a DNA (Costello Syndrome)
- Environmental factors like:
a) Infection & diseases during pregnancy, such as rubella, diabetes, lupus, etc.
b) Drug related abnormalities (from hydantoin, thalidomide & lithium).
c) Alcohol exposure in the father.
d) Maternal obesity during pregnancy.
DIAGNOSIS OF CHD
- CHD can be diagnosed prenatally by fetal echocardiography, done during the second trimester of pregnancy by an abdominal or transvaginal ultrasound.
- Cyanotic heart defect is detected by the bluish grey discoloration of the skin of the baby just after it is born.
- Obstructive defects are noticed after several months or even years.
TREATMENT & MANAGEMENT OF CHD
- Antibiotic drugs to prevent & manage infections of the heart lining.
- Diuretics which aid the body to eliminate salt.
- Digoxin for strengthening the contraction of the heart.
- Heart implants to manage abnormal heart rhythm, like pacemakers & ICDs.
- Use of techniques that utilize catheters for correction of some defects.
- Heart surgery
- Heart transplant
- Prevention by;
- Rubella vaccination for the mothers.
- Addition of salt to iodine & folic acid to food.
- Moderate alcohol consumption.
- Careful drug intake.
- Management of comorbities in parents like diabetes, lupus, etc.