Congenital Heart Disease

What is Congenital Heart Disease?

Congenital heart diseases (CHD) are the cardiac conditions present at birth, caused because of abnormal structures of the heart or the cardiovascular system. These diseases develop during the growth of the fetus in the womb. The symptoms of CHD may be apparent in childhood, but some patients may not have any symptoms until adulthood.

Symptoms of Congenital Heart Disease

The symptoms of CHD in adults include:

• Shortness of breath
• Getting tired faster during exercise (poor exercise tolerance).
• Heart murmurs
• Bluish discolouration of the skin and mucous membranes (cyanosis)

The common congenital heart diseases affecting adults include:

• Congenital valve defects: Congenital valve defects occur when valves have not formed correctly before birth. Valve defects may arise from improper size, malformation of leaflets or inappropriate attachment of leaflets to annulus. It commonly affects the aortic or pulmonic valve.
• Bicuspid aortic valve disease is a congenital valve disease in which there are only two leaflets in the aortic valve instead of three. This results in a stiff, leaky valve that does not open or closes properly.
• Atrial and ventricular septal defects: An atrial septal defect (ASD) is the condition of a defective muscular wall (septum) that separates the two upper chambers of the heart. It is because of the poorly developed atrial septum. A ventricular septal defect (VSD) is a condition of the defective septum that separates the lower chambers of the heart. The hole or defect in the septum allows the mixing of blood in the right and left chambers of the heart.
• Patent foramen ovale: During fetal development in the womb, a small hole is seen in the atrial septum of the fetus, through which blood travels from the right side of the heart to the left. This small hole is called as foramen ovale. It normally closes at birth, but if it does not close properly, it is called a patent foramen ovale. This defect acts as a flap valve that opens only when there is increased pressure inside the chest caused by coughing, sneezing or bowel movement. If the pressure is more, blood may travel from the right atrium to the left atrium.
• Patent Ductus Arteriosus: Patent ductus arteriosus is a congenital heart defect in which there is an abnormal connection between the aorta and the pulmonary artery that is present at birth. While in the womb, the aorta and the pulmonary artery in the fetus are connected by a vessel, the ductus arteriosus as a part of fetal circulation which seals off after birth. If the vessels fail to close after birth, it leads to the condition, patent ductus arteriosus, which causes the mixing of blood in the aorta and the pulmonary artery.
• Coarctation of the Aorta: Coarctation of the aorta is a common congenital heart defect caused by narrowing of the aorta at one site or along the portion of its length. This results in restricted blood flow through the aorta. The symptoms include shortness of breath, headache, chest pain, exercise intolerance, bleeding from the nose, and leg pain.
• Ebstein's Anomaly: Ebstein's anomaly is a rare congenital heart defect in which the tricuspid valve guarding the passage between the right atrium and right ventricle does not close properly. The flaps of the tricuspid valve have an abnormal shape, either too large or adhering to the heart wall, making them unable to move. As a result, the valve does not open and close properly and may cause the backflow of blood from the ventricle into the atrium while pumping.
• Pulmonary Artery Stenosis: Pulmonary artery stenosis is a congenital heart defect caused by the narrowing of the pulmonary artery that carries impure blood into the lungs. This makes the flow of blood to the lungs difficult.
• Tetralogy of Fallot: Tetralogy of Fallot is a rare, congenital heart defect which is a group of four heart defects including large ventricular septal defect, pulmonary stenosis, right ventricular hypertrophy, and an overriding aorta. In Tetralogy of Fallot, the aorta is located between the left and right ventricles, above the ventricular septal defect.
• Pulmonary Hypertension: Pulmonary hypertension is a rare disorder of the lungs in which there is the narrowing of the arteries that carry blood to the lungs from the heart. It makes blood flow through these vessels difficult, as a result of which the blood pressure of pulmonary arteries rises above normal levels. This high blood pressure strains the right ventricle of the heart leading to its enlargement. Enlarged right ventricle may lose its capacity to pump enough blood and may cause right heart failure.

Diagnosis of Congenital Heart Disease

Congenital heart diseases are diagnosed by listening to heart murmurs using a stethoscope and other diagnostic tests such as:

• Echocardiogram: Echocardiogram is done to assess the overall function of the heart.
• Transesophageal echocardiogram: This is a type of echo test in which the ultrasound transducer is guided into the oesophagus through the patient's throat with an endoscope.
• Intravascular ultrasound (IVUS): It is performed along with cardiac catheterization. A small sound probe (transducer) placed at the tip of a coronary catheter is guided through the coronary arteries. It uses high-frequency sound waves to produce cross-sectional images of the interior walls of the arteries in detail.
• Cardiac catheterization: It is an invasive imaging procedure used to evaluate heart function. It confirms the presence of coronary artery disease, valve disease or disease of the aorta
• Chest X-ray: Chest X-ray helps to detect heart and lung diseases.
• Electrocardiogram (ECG): Electrocardiogram is done to detect abnormalities of the heart such as heart chamber enlargement and abnormal electrical activity.
• Magnetic resonance imaging (MRI) scan: MRI scan creates moving images of the heart throughout the pumping cycle and acquires information about the heartbeat.
• Positron emission tomography (PET) scan: PET scan is a diagnostic test that includes the injection of radioactive material into the vein and assessing the blood flow to various parts.

Treatment for Congenital Heart Disease

Treatment depends on the type and severity of the heart defect. Mild heart defects do not require any treatment. Other defects may require medications, surgery or invasive procedures. Adults with congenital heart disease should take precautionary medications to prevent endocarditis and be monitored regularly by a cardiologist.